LivePerson (LPSN) 10-K 25 Feb 19 2018 FY Annual report Financial data

Document and Entity Information

Document and Entity Information - USD ($)	12 Months Ended
	Dec. 31, 2018	Feb. 19, 2019	Jun. 30, 2018
Document - Document And Entity Information [Abstract]
Entity Registrant Name	LIVEPERSON INC
Entity Central Index Key	1,102,993
Trading Symbol	lpsn
Current Fiscal Year End Date	--12-31
Entity Filer Category	Large Accelerated Filer
Document Type	10-K
Document Period End Date	Dec. 31, 2018
Document Fiscal Year Focus	2,018
Document Fiscal Period Focus	FY
Amendment Flag	false
Entity Common Stock, Shares Outstanding		63,936,625
Entity Well-known Seasoned Issuer	Yes
Entity Voluntary Filers	No
Entity Current Reporting Status	Yes
Entity Public Float			$ 1,202,579,414

Consolidated Balance Sheets

Consolidated Balance Sheets - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
CURRENT ASSETS:
Cash and cash equivalents	$ 66,449	$ 56,115
Cash held as collateral	0	1,451
Accounts receivable, net of allowance for doubtful accounts of $2,276 and $1,318, in 2018 and 2017, respectively	46,023	37,926
Prepaid expenses and other current assets	22,613	7,352
Total current assets	135,085	102,844
Property and equipment, net	43,735	34,705
Intangibles, net	13,832	12,366
Goodwill	95,031	80,531
Deferred tax assets, net	713	753
Other assets	1,707	1,600
Total assets	290,103	232,799
CURRENT LIABILITIES:
Accounts payable	8,174	5,481
Accrued expenses and other current liabilities	50,662	48,011
Deferred revenue	55,015	35,563
Total current liabilities	113,851	89,055
Deferred revenue	222	0
Other liabilities	4,205	2,766
Deferred tax liability	1,096	915
Total liabilities	119,374	92,736
Commitments and contingencies (See Note 9)
STOCKHOLDERS' EQUITY:
Common stock	64	60
Additional paid-in capital	362,590	305,676
Treasury stock	(3)	(3)
Accumulated deficit	(187,491)	(163,135)
Accumulated other comprehensive loss	(4,431)	(2,535)
Total stockholders’ equity	170,729	140,063
Total liabilities and stockholders’ equity	$ 290,103	$ 232,799

Consolidated Balance Sheets (Pa

Consolidated Balance Sheets (Parenthetical) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Statement of Financial Position [Abstract]
Accounts receivable, allowance for doubtful accounts	$ 2,276	$ 1,318

Consolidated Statements of Oper

Consolidated Statements of Operations - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Revenue	$ 249,838	$ 218,876	$ 222,779
Costs and expenses:
Cost of revenue	62,479	58,205	63,161
Sales and marketing	103,344	90,905	89,529
General and administrative	45,873	43,124	43,046
Product development	55,707	40,034	40,198
Restructuring costs	4,468	2,594	2,369
Amortization of purchased intangibles	1,670	1,840	3,885
Total costs and expenses	273,541	236,702	242,188
Loss from operations	(23,703)	(17,826)	(19,409)
Other (expense) income, net	(471)	136	(530)
Loss before provision for income taxes	(24,174)	(17,690)	(19,939)
Provision for income taxes	858	501	5,934
Net loss	$ (25,032)	$ (18,191)	$ (25,873)
Net loss per share of common stock:
Basic (in dollars per share)	$ (0.42)	$ (0.32)	$ (0.46)
Diluted (in dollars per share)	$ (0.42)	$ (0.32)	$ (0.46)
Weighted-average shares used to compute net loss income per share:
Basic (in shares)	59,203,400	56,358,017	56,063,777
Diluted (in shares)	59,203,400	56,358,017	56,063,777
Additional Information on Operating Expenses:
Stock compensation expense	$ 14,841	$ 8,944	$ 9,736
Cost Of Revenue [Member]
Additional Information on Operating Expenses:
Stock compensation expense	996	448	429
Depreciation expense	7,831	7,150	8,234
Amortization of purchased intangibles	1,143	2,842	2,788
Sales and Marketing [Member]
Additional Information on Operating Expenses:
Stock compensation expense	5,374	2,500	2,515
Depreciation expense	1,520	1,625	1,315
General and Administrative [Member]
Additional Information on Operating Expenses:
Stock compensation expense	4,921	3,691	3,304
Depreciation expense	1,083	1,226	1,418
Product Development [Member]
Additional Information on Operating Expenses:
Stock compensation expense	3,550	2,305	3,488
Depreciation expense	$ 3,754	$ 2,357	$ 1,044

Consolidated Statements of Comp

Consolidated Statements of Comprehensive Loss - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Statement of Comprehensive Income [Abstract]
Net loss	$ (25,032)	$ (18,191)	$ (25,873)
Foreign currency translation adjustment	(1,896)	3,625	(3,624)
Comprehensive loss	$ (26,928)	$ (14,566)	$ (29,497)

Consolidated Statements of Stoc

Consolidated Statements of Stockholders' Equity - USD ($) $ in Thousands	Total	Common Stock	Treasury Stock	Additional Paid-In Capital	Accumulated Deficit	Accumulated Other Comprehensive Loss
Beginning Balance (in shares) at Dec. 31, 2015		57,374,907	(821,756)
Beginning Balance at Dec. 31, 2015	$ 165,305	$ 57	$ (1)	$ 286,856	$ (119,071)	$ (2,536)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock issued upon exercise of stock options (in shares)	325,000	324,502
Common stock issued upon exercise of stock options	$ 1,806			1,806
Common stock issued upon vesting of restricted stock units (in shares)		393,504
Common stock issued upon vesting of restricted stock units	1	$ 1
Stock-based compensation	9,736			9,736
Common stock issued under Employee Stock Purchase Plan (in shares)		183,534
Common stock issued under Employee Stock Purchase Plan	1,092			1,092
Common stock repurchase (in shares)			(1,518,349)
Common stock repurchase	(9,967)		$ (1)	(9,966)
Net loss	(25,873)				(25,873)
Other comprehensive income (loss)	(3,624)					(3,624)
Ending Balance (in shares) at Dec. 31, 2016		58,276,447	(2,340,105)
Ending Balance at Dec. 31, 2016	$ 138,476	$ 58	$ (2)	289,524	(144,944)	(6,160)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock issued upon exercise of stock options (in shares)	854,000	853,885
Common stock issued upon exercise of stock options	$ 7,491	$ 1		7,490
Common stock issued upon vesting of restricted stock units (in shares)		363,429
Common stock issued upon vesting of restricted stock units	1	$ 1
Stock-based compensation	8,944			8,944
Common stock issued under Employee Stock Purchase Plan (in shares)		170,208
Common stock issued under Employee Stock Purchase Plan	1,459			1,459
Common stock repurchase (in shares)			(247,430)
Common stock repurchase	(1,742)		$ (1)	(1,741)
Net loss	(18,191)				(18,191)
Other comprehensive income (loss)	3,625					3,625
Ending Balance (in shares) at Dec. 31, 2017		59,663,969	(2,587,535)
Ending Balance at Dec. 31, 2017	$ 140,063	$ 60	$ (3)	305,676	(163,135)	(2,535)
Increase (Decrease) in Stockholders' Equity [Roll Forward]
Common stock issued upon exercise of stock options (in shares)	3,120,000	3,120,404
Common stock issued upon exercise of stock options	$ 32,791	$ 3		32,788
Common stock issued upon vesting of restricted stock units (in shares)		361,539
Common stock issued upon vesting of restricted stock units	1	$ 1
Stock-based compensation	14,841			14,841
Common stock issued under Employee Stock Purchase Plan (in shares)		150,989
Common stock issued under Employee Stock Purchase Plan	2,480			2,480
Common stock repurchase (in shares)			(93,750)
Common stock repurchase	(1,345)		$ 0	(1,345)
ASC 606 prior period adjustment	676
Issuance of common stock in connection with acquisitions (in shares)		379,328
Issuance of common stock in connection with acquisitions	8,150			8,150
Net loss	(25,032)
Other comprehensive income (loss)	(1,896)					(1,896)
Ending Balance (in shares) at Dec. 31, 2018		63,676,229	(2,681,285)
Ending Balance at Dec. 31, 2018	$ 170,729	$ 64	$ (3)	$ 362,590	$ (187,491)	$ (4,431)

Consolidated Statements of Cash

Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
OPERATING ACTIVITIES:
Net loss	$ (25,032)	$ (18,191)	$ (25,873)
Adjustments to reconcile net loss to net cash provided by operating activities:
Stock-based compensation expense	14,841	8,944	9,736
Depreciation	14,188	12,358	12,011
Impairment on investments	0	0	2,600
Amortization of tenant allowance	(326)	(166)	(180)
Amortization of purchased intangibles	2,813	4,682	6,673
Provision for doubtful accounts, net	1,788	1,895	1,831
Deferred income taxes	(309)	(2,397)	1,852
Changes in operating assets and liabilities, net of acquisitions:
Accounts receivable	(9,662)	(7,998)	(3,265)
Prepaid expenses and other current assets	(14,628)	(1,867)	3,845
Other assets	(107)	(38)	196
Accounts payable	2,199	(2,743)	185
Accrued expenses and other current liabilities	(205)	7,838	2,982
Deferred revenue	19,005	8,418	13,283
Other liabilities	214	(445)	(1,316)
Net cash provided by operating activities	4,779	10,290	24,560
INVESTING ACTIVITIES:
Purchases of property and equipment, including capitalized software	(21,938)	(17,390)	(12,344)
Payments for acquisitions and intangible assets, net of cash acquired	(7,286)	(441)	(555)
Cash held as collateral	1,451	2,511	1,447
Net cash used in investing activities	(27,773)	(15,320)	(11,452)
FINANCING ACTIVITIES:
Repurchase of common stock	(1,345)	(1,742)	(9,967)
Proceeds from issuance of common stock in connection with the exercise of options	35,271	8,951	2,899
Net cash provided by (used in) financing activities	33,926	7,209	(7,068)
EFFECT OF FOREIGN EXCHANGE RATE CHANGES ON CASH AND CASH EQUIVALENTS	(598)	3,047	(3,954)
CHANGE IN CASH AND CASH EQUIVALENTS	10,334	5,226	2,086
CASH AND CASH EQUIVALENTS - Beginning of the year	56,115	50,889	48,803
CASH AND CASH EQUIVALENTS - End of the year	66,449	56,115	50,889
SUPPLEMENTAL DISCLOSURE OF OTHER CASH FLOW INFORMATION:
Cash paid for income taxes	5,144	1,551	424
SUPPLEMENTAL DISCLOSURE OF NON-CASH INVESTING AND FINANCING ACTIVITIES:
Purchase of property and equipment recorded in accounts payable	190	936	2,497
Leasehold improvements funded by landlord	1,551	0	1,440
BotCentral
SUPPLEMENTAL DISCLOSURE OF NON-CASH INVESTING AND FINANCING ACTIVITIES:
Issuance of shares of common stock in connection with acquisition	$ 1,000	0	0
Issuance of shares of common stock in connection with acquisition (in shares)	85,861,000
Conversable
SUPPLEMENTAL DISCLOSURE OF NON-CASH INVESTING AND FINANCING ACTIVITIES:
Issuance of shares of common stock in connection with acquisition	$ 2,850	0	0
Issuance of shares of common stock in connection with acquisition (in shares)	115,385,000
Fair value of contingent earn-out in connection with the acquisition recorded in accrued expenses	$ 1,496	0	0
AdvantageTec
SUPPLEMENTAL DISCLOSURE OF NON-CASH INVESTING AND FINANCING ACTIVITIES:
Issuance of shares of common stock in connection with acquisition	$ 4,300	0	0
Issuance of shares of common stock in connection with acquisition (in shares)	117,082,000
Fair value of contingent earn-out in connection with the acquisition recorded in accrued expenses	$ 876	$ 0	$ 0

Description of Business and Sum

Description of Business and Summary of Significant Accounting Policies	12 Months Ended
	Dec. 31, 2018
Accounting Policies [Abstract]
Description of Business and Summary of Significant Accounting Policies	Description of Business and Summary of Significant Accounting Policies LivePerson, Inc. (the “Company” or “LivePerson”) was incorporated in the State of Delaware in November 1995 and the LivePerson service was introduced in November 1998. In April 2000, the company completed an initial public offering and is currently traded on the NASDAQ Global Select Market and the Tel Aviv Stock Exchange. LivePerson is headquartered in New York City with U.S. offices in Alpharetta (Georgia), Austin (Texas), San Francisco (California) and Seattle (Washington), and international offices in Amsterdam (Netherlands), Berlin (Germany), London (United Kingdom), Mannheim (Germany), Melbourne (Australia), Milan (Italy), Paris (France), Ra'anana (Israel), Reading (United Kingdom), Tel Aviv (Israel), and Tokyo (Japan). LivePerson makes life easier by transforming how people communicate with brands. During the past decade, the consumer has made the mobile device the center of their digital lives, and they have made mobile messaging the center of communication with friends, family and peers. The Company’s technology enables consumers to connect with businesses through these same preferred conversational interfaces, including Facebook Messenger, WhatsApp, Apple Business Chat, Google Rich Business Messenger and Alexa. These messaging conversations harness human agents, bots and Artificial Intelligence (AI) to power convenient, personalized and content-rich journeys across the entire consumer lifecycle, from discovery and research, to sales, service and support, and even marketing and brick and mortar engagements. For example, consumers can look up product info like ratings, images and pricing, search for stores, see products in the store, schedule appointments, apply for credit, approve repairs, make purchases or payments - all without ever leaving the messaging channel. LivePerson calls these AI and human-assisted conversational experiences over messaging Conversational Commerce. LiveEngage, the Company’s enterprise-class, cloud-based platform, was designed for Conversational Commerce, enabling businesses to securely deploy messaging, coupled with bots and AI, at scale for brands with tens of millions of customers and many thousands of customer care agents. LiveEngage powers conversations across each of a brand’s primary digital channels, including mobile apps, mobile and desktop web browsers, short message service (SMS), social media and third-party consumer messaging platforms. Brands can also use LiveEngage to message consumers when they dial a 1-800 number instead of having them navigate interactive voice response systems (IVRs) and wait on hold. The robust, cloud-based suite of rich mobile messaging and real-time chat offerings features intelligent routing and capacity mapping, queue prioritization, customer sentiment, real-time analytics and reporting, content delivery, Payment Card Industry (PCI) compliance, cobrowsing and a sophisticated proactive targeting engine. With LiveEngage, agents can manage all conversations with consumers through a single console interface, regardless of which disparate messaging endpoints the consumers originate from: i.e., WhatsApp, Line, Apple Business Chat, IVR, or Google Home. An extensible application programming interface (API) stack facilitates a lower cost of ownership by facilitating robust integration into back-end systems, as well as enabling developers to build their own programs and services on top of the platform. More than three dozen APIs are available on LiveEngage. LiveEngage also features Maven, a robust AI engine that was custom designed for Conversational Commerce. Maven, announced in December 2018, puts the power of bot development, training and management into the hands of the contact center and its agents, the teams most familiar with how to structure sales and service conversations to drive successful outcomes. The platform enables what the Company calls “the tango” of humans, AI and bots, whereby human agents act as bot managers, overseeing AI-powered conversations and seamlessly stepping into the flow when a personal touch is needed. Through Maven Assist, agents become ultra-efficient, leveraging the AI engine to serve up relevant content, define next-best actions and take over repetitive transactional work, so that the agent can focus on relationship building. By seamlessly integrating LiveEngage with Maven, as well as third-party bots, the platform provides businesses with a comprehensive view of all AI-based and human-based conversations from a single console. Complementing LiveEngage are teams of technical, solutions and consulting professionals that have developed deep domain expertise in Conversational Commerce across industries and messaging endpoints. The Company is positioned as an authority in Conversational Commerce, publishing a proprietary Conversational Quotient™ Index that measures each customer across multiple key indicators to ascertain their level of conversational maturity. Each business is then benchmarked against industry peers to determine their relative progression. The Company has developed a Transformation Model that is introduced to existing and prospective customers to help guide them on their journeys from legacy and oftentimes inefficient legacy voice, email and chat solutions to modern conversational ones powered by messaging and AI. LivePerson’s products, coupled with our domain knowledge, industry expertise and professional services, have been proven to maximize the effectiveness of Conversational Commerce and deliver measurable return on investment. As a “cloud computing” or software-as-a-service (SaaS) provider, LivePerson provides solutions on a hosted basis. This model offers significant benefits over premise-based software, including lower up-front costs, faster implementation, lower total cost of ownership, scalability, cost predictability, and simplified upgrades. Organizations that adopt a fully-hosted, multi-tenant architecture that is maintained by LivePerson eliminate the majority of the time, server infrastructure costs, and IT resources required to implement, maintain, and support traditional on-premise software. Our consumer services offering is an online marketplace that connects independent service providers (Experts) who provide information and knowledge for a fee via mobile and online messaging with individual consumers (Users). Users seek assistance and advice in various categories including personal counseling and coaching, computers and programming, education and tutoring, spirituality and religion, and other topics. Principles of Consolidation The consolidated financial statements reflect the operations of LivePerson and its wholly-owned subsidiaries. All significant intercompany balances and transactions have been eliminated in consolidation. Reclassification For comparability, certain 2016 and 2017 amounts have been reclassified where appropriate, to conform to the financial presentation in 2018 . Use of Estimates The preparation of the consolidated financial statements in accordance with accounting principles generally accepted in the United States of America (“GAAP”) requires the Company’s management to make a number of estimates and assumptions relating to the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the consolidated financial statements and the reported amounts of revenue and expenses during the period. Significant items subject to such estimates and assumptions include revenue recognition, stock-based compensation, accounts receivable, the valuation of goodwill and intangible assets, income taxes and legal contingencies. Actual results could differ from those estimates. Concentration of Credit Risk Financial instruments that potentially subject the Company to significant concentrations of credit risk consist primarily of cash and cash equivalents and accounts receivable which approximate fair value at December 31, 2018 because of the short-term nature of these instruments. The Company invests its cash and cash equivalents with financial institutions that it believes are of high quality, and the Company performs periodic evaluations of these instruments and the relative credit standings of the institutions with which it invests. At certain times, the Company’s cash balances with any one financial institution may exceed Federal Deposit Insurance Corporation insurance limits. The Company believes it mitigates its risk by depositing its cash balances with high credit, quality financial institutions. The Company performs ongoing credit evaluations of its customers’ financial condition (except for customers who purchase the LivePerson services by credit card via Internet download) and has established an allowance for doubtful accounts based upon factors surrounding the credit risk of customers, historical trends and other information. Concentration of credit risk is limited due to the Company’s large number of customers. No single customer accounted for or exceeded 10% of revenue in 2018 , 2017 or 2016 . One customer exceeded 10% of the Company's total accounts receivable in 2018 with a balance of approximately approximately $10.0 million . No single customer accounted for or exceeded 10% of the Company's total accounts receivable in 2017 . Foreign Currency Translation The Company's operations are conducted in various countries around the world and the financial statements of its foreign subsidiaries are reported in the applicable foreign currencies (functional currencies). Financial information is translated from the applicable functional currency to the U.S. dollar (the reporting currency) for inclusion in the Company's consolidated financial statements. Income, expenses and cash flows are translated at weighted average exchange rates prevailing during the fiscal period, and assets and liabilities are translated at fiscal period-end exchange rates. Resulting translation adjustments are included as a component of accumulated other comprehensive income (loss) in stockholders' equity. Foreign exchange transaction gain or losses are included in Other Income, net in the accompanying consolidated statements of operations. Cash and Cash Equivalents The Company considers all highly liquid securities with original maturities of three months or less when acquired to be cash equivalents. Cash equivalents, which primarily consist of money market funds, are recorded at cost, which approximates fair value. Accounts Receivable Accounts receivable are recorded at the invoiced amount and do not bear interest. The allowance for doubtful accounts is the Company’s best estimate of the amount of probable credit losses in the Company’s existing accounts receivable. The Company determines the allowance based on historical write-off experience. The Company reviews its allowance for doubtful accounts monthly. Past due balances over 90 days and over a specified amount are reviewed individually for collectability. All other balances are reviewed on a pooled basis. Account balances are charged off against the allowance after all means of collection have been exhausted and the potential for recovery is considered remote. The Company does not have any off-balance sheet credit exposure related to its customers. The activity in the allowance for doubtful accounts is as follows (amounts in thousands): Year Ended December 31, Beginning Balance Additions Charged to Costs and Expenses Deductions / Write-Offs Ending Balance 2016 $ 1,184 $ 1,831 $ (1,283 ) $ 1,732 2017 $ 1,732 $ 1,895 $ (2,309 ) $ 1,318 2018 $ 1,318 $ 1,814 $ (856 ) $ 2,276 Property and Equipment Property and equipment are stated at cost, net of accumulated depreciation. Depreciation is calculated using the straight-line method over the estimated useful lives of the related assets, generally three to five years for equipment and software. Leasehold improvements are depreciated using the straight-line method over the shorter of the lease term or the estimated useful life of the asset. Depreciation expense, which includes depreciation of internal use software totaled $14.2 million , $12.4 million , and $12.0 million for the years ended December 31, 2018 , 2017 and 2016 , respectively. Internal-Use Software Development Costs In accordance with the Financial Accounting Standards Board (“FASB”) Accounting Standards Codification (“ASC”) 350-40, "Internal-Use Software", the Company capitalizes its costs to develop its internal use software when preliminary development efforts are successfully completed, management has authorized and committed project funding, and it is probable that the project will be completed and the software will be used as intended. These costs are included in property and equipment in the Company's consolidated balance sheets and are amortized on a straight-line basis over the estimated useful life of the related asset, which approximates three years. Costs incurred prior to meeting these criteria, together with costs incurred for training and maintenance, are expensed as incurred. The Company capitalized internal-use software costs of $11.7 million , $8.3 million , and $3.7 million for the years ended December 31, 2018 , 2017 and 2016 , respectively. Goodwill and Intangible Assets The Company records goodwill when the consideration paid in a business combination exceeds the fair value of the net tangible assets and the identified intangible assets acquired. Goodwill is not amortized, but instead is required to be tested for impairment annually and whenever events or changes in circumstances indicate that the carrying value of goodwill may exceed its fair value. The Company performs testing for impairment of goodwill in its third quarter, or as events occur or circumstances change that would more likely than not reduce the fair value of the Company’s reporting units below their carrying amounts. A qualitative assessment is first made to determine whether it is necessary to perform the two-step quantitative goodwill impairment test. This initial qualitative assessment includes, among other things, consideration of: (i) market capitalization of the Company, (ii) past, current and projected future earnings and equity; (iii) recent trends and market conditions; and (iv) valuation metrics involving similar companies that are publicly-traded and acquisitions of similar companies, if available. If this initial qualitative assessment indicates that it is more likely than not that impairment exists, a second analysis will be performed, involving a comparison between the estimated fair values of the Company’s reporting unit with its respective carrying amount including goodwill. If the carrying value exceeds estimated fair value, there is an indication of potential impairment, and a third analysis is performed to measure the amount of impairment. The third analysis involves calculating an implied fair value of goodwill by measuring the excess of the estimated fair value of the reporting unit over the aggregate estimated fair values of the individual assets less liabilities. If the carrying value of goodwill exceeds the implied fair value of goodwill, an impairment charge is recorded for the excess. Intangible assets with estimable useful lives are amortized over their respective estimated useful lives to their estimated residual values, and reviewed for impairment in accordance with ASC 360-10-35, “Accounting for Impairment or Disposal of Long-Lived Assets.” The Company evaluates for goodwill impairment annually at September 30 th and at the end of the third quarter of 2018 , 2017 , and 2016 , the Company determined that it was not more-likely that the fair value of the reporting units is less than their carrying amount. Accordingly, the Company did not perform the two-step goodwill impairment test on both the Company's Business and Consumer segments. The Company assessed qualitative facts while summarizing the totality of events and circumstances and considered the extent to which adverse events or circumstances could affect the reporting unit's fair value as well as the consideration of positive and mitigating events and circumstances that would affect the determination of whether it was more likely than not that the fair value of a reporting unit is less than its carrying amount. Business Combinations Business combinations are accounted for using the acquisition method and accordingly, the assets acquired (including identified intangible assets), the liabilities assumed and any noncontrolling interest in the acquired business are recorded at their acquisition date fair values. The Company’s acquisition model typically provides for an initial payment at closing and for future additional contingent purchase price obligations. Contingent purchase price obligations are recorded as deferred acquisition consideration on the balance sheet at the acquisition date fair value and are remeasured at each reporting period. Changes in such estimated values are recorded in the results of operations. For further information, see Note 7 of the Notes to the Consolidated Financial Statements included herein. For the years ended December 31, 2018, $0.6 million of acquisition related costs were charged to operations. For each acquisition, the Company undertakes a detailed review to identify other intangible assets and a valuation is performed for all such identified assets. The Company uses several market participant measurements to determine estimated value. This approach includes consideration of similar and recent transactions, as well as utilizing discounted expected cash flow methodologies. A substantial portion of the intangible asset value that the Company acquires is the specialized know-how of the workforce, which is treated as part of goodwill and is not required to be valued separately. The majority of the value of the identifiable intangible assets acquired is derived from customer relationships, including the related customer contracts, as well as trade names. In executing the Company’s overall acquisition strategy, one of the primary drivers in identifying and executing a specific transaction is the existence of, or the ability to, expand the existing client relationships. The expected benefits of the Company’s acquisitions are typically shared across multiple agencies and regions. Impairment of Long-Lived Assets In accordance with ASC 360-10, “Accounting for the Impairment or Disposal of Long-lived Assets,” long-lived assets, such as property, plant and equipment and purchased intangibles subject to amortization are reviewed for impairment whenever events or changes in circumstances indicate that the carrying value of an asset may not be recoverable. The amount of any impairment is measured as the difference between the carrying value and the fair value of the impaired asset. Revenue Recognition The majority of the Company’s revenue is generated from monthly service revenues and related professional services from the sale of the LivePerson services. Revenues are recognized when control of these services is transferred to the Company's customers, in an amount that reflects the consideration the Company expects to be entitled to in exchange for those services. The Company determines revenue recognition through the following steps: • Identification of the contract, or contracts, with a customer; • Identification of the performance obligations in the contract; • Determination of the transaction price; • Allocation of the transaction price to the performance obligations in the contract; and • Recognition of revenue when, or as, the Company satisfies a performance obligation. Total revenue of $249.8 million recognized during the year ended December 31, 2018 , under Topic 606, was not materially different from what would have been recognized under Topic 605. The Company has made the following accounting policy election and elected to use a practical expedient specific to certain revenue streams, as permitted by the FASB, in applying Topic 606. The Company utilizes the right-to-invoice practical expedient with regard to the recognition of revenue upon the invoicing of certain revenue streams, as revenue for those streams are billed monthly Hosted Services- Business Revenue Hosted Services Business revenue is reported at the amount that reflects the ultimate consideration expected to be received and primarily consist of fees that provide customers access to LiveEngage, the Company’s enterprise-class, cloud-based platform. The Company has determined such access represents a stand-ready service provided continually throughout the contract term. As such, control and satisfaction of this stand-ready performance obligation is deemed to occur over time. The Company recognizes this revenue over time on a ratable basis over the contract term, beginning on the date that access to the LiveEngage platform is made available to the customer. The passage of time is deemed to be the most faithful depiction of the transfer of control of the services as the customer simultaneously receives and consumes the benefit provided by the Company’s performance. Subscription contracts are generally one year or longer in length, billed, monthly, quarterly or annually in advance. There is no significant variable consideration related to these arrangements. Additionally, for certain of the Company's larger customers, the Company may provide call center labor through an arrangement with one or more of several qualified vendors. For most of these customers, the Company passes the fee it incurs with the labor provider and its fee for the hosted services through to its customers in the form of a fixed fee for each order placed via the Company's online engagement solutions. For these Pay for Performance ("PFP") arrangements in accordance with ASC-606, "Principal Agent Considerations", the Company acts as a principal in a transaction if it controls the specified goods or services before they are transferred to the customer. Professional Services Revenues Professional services revenue primarily consists of fees for deployment and optimization services, as well as training delivered on an on-demand basis which is deemed to represent a distinct stand-ready performance obligation. Professional Services Revenues are reported at the amount that reflects the ultimate consideration the Company expects to receive in exchange for such services. Control for the majority of the Company's Professional Services contracts passes over time to the customer and is recognized ratably over the contracted period, as the passage of time is deemed to be the most faithful depiction of the transfer of control. For certain deployment services, which are not deemed to represent a distinct performance obligation, revenue will be recognized in the same manner as the fee for access to the LiveEngage platform, and as such will be recognized on a straight-line basis over the contract term. For services billed on a fixed price basis, revenue is recognized over time based on the proportion performed using inputs as the measure of progress toward complete satisfaction of the performance obligation. Professional service contracts are generally one year or longer in length, billed, monthly, quarterly or annually in advance. There is no significant variable consideration related to these arrangements. Contracts with Multiple Performance Obligations Some of the Company's contracts with customers contain multiple performance obligations. For these contracts, the Company accounts for individual performance obligations separately if they are distinct. The transaction price is allocated to the separate performance obligations on a relative standalone selling price basis. The Company determines the standalone selling prices based on its overall pricing objectives, taking into consideration market conditions and other factors, including the value of its contracts, the cloud applications sold, and the number and types of users within its contracts. Hosted Services- Consumer Revenue For revenue from the Company's Consumer segment generated from online transactions between Experts and Users, revenue is recognized at an amount net of Expert fees in accordance with ASC 606, “Principal Agent Considerations,” due primarily to the fact that the Expert is the primary obligor. Additionally, the Company performs as an agent without any risk of loss for collection, and is not involved in selecting the Expert or establishing the Expert’s fee. The Company collects a fee from the consumer and retains a portion of the fee, and then remits the balance to the Expert. Revenue from these transactions is recognized at the point in time when the transaction is complete and no significant performance obligations remain. Deferred Revenues The Company records deferred revenues when cash payments are received or due in advance of its performance. The increase in the deferred revenue balance for the year ended December 31, 2018 is primarily driven by cash payments received or due in advance of satisfying its performance obligations, partially offset by $32.7 million of revenues recognized that were included in the deferred revenue balance as of December 31, 2017 . The following table presents deferred revenue by revenue source (amounts in thousands): December 31, 2018 2017 Hosted services – Business $ 52,232 $ 27,011 Professional services – Business 2,783 8,552 Total deferred revenue - short term $ 55,015 $ 35,563 Hosted services – Business $ 19 $ — Professional services – Business 203 — Total deferred revenue - long term $ 222 $ — Disaggregated Revenue The following table presents the Company's revenues disaggregated by revenue source (amounts in thousands): December 31, 2018 2017 2016 Revenue: Hosted services – Business $ 197,474 $ 178,686 $ 183,551 Hosted services – Consumer 19,553 17,450 16,258 Professional services 32,811 22,740 22,970 Total revenue $ 249,838 $ 218,876 $ 222,779 Revenue by Geographic Location The Company is domiciled in the United States and has international operations in the United Kingdom, Asia-Pacific, Latin America and Western Europe, particularly France and Germany. The following table presents the Company's revenues attributable to domestic and foreign operations for the years ended (amounts in thousands): December 31, 2018 2017 2016 United States $ 146,702 $ 137,433 $ 146,733 Other Americas (1) 7,315 6,987 6,818 Total Americas 154,017 144,420 153,551 EMEA (2) (4) 71,318 56,310 50,511 APAC (3) 24,503 18,146 18,717 Total revenue $ 249,838 $ 218,876 $ 222,779 (1) Canada, Latin America and South America (2) Europe, the Middle East and Africa (“EMEA”) (3) Asia-Pacific (“APAC”) (4) Includes revenue from the United Kingdom of $46.5 million , $38.9 million , and $35.3 million for the year ended December 31, 2018 , 2017 , and 2016 , respectively. and from the Netherlands of $8.7 million , $2.0 million , and $2.1 million for the year ended December 31, 2018 , 2017 , and 2016 , respectively. Information about Contract Balances Amounts collected in advance of services being provided are accounted for as deferred revenue. Nearly all of the Company's deferred revenue balance is related to Hosted Services- Business Revenue. In some arrangements, the Company allows customers to pay for access to LiveEngage over the term of the software license. The Company refers to these as subscription transactions. Amounts recognized as revenue in excess of amounts billed are recorded as unbilled receivables. Unbilled receivables, anticipated to be invoiced in the next twelve months, are included in accounts receivable on the consolidated balance sheet. The opening and closing balances of the Company's accounts receivable, unbilled receivables, and deferred revenues are as follows (amounts in thousands): Accounts Receivable Unbilled Receivable Prepaid Commissions Deferred Revenue (current) Deferred Revenue (long term) Opening Balance as of December 31, 2017 $ 30,342 $ 7,584 $ 2,223 $ 35,563 $ — Increase (decrease), net 3,869 4,228 11,138 19,452 222 Ending Balance as of December 31, 2018 $ 34,211 $ 11,812 $ 13,361 $ 55,015 $ 222 As of December 31, 2018 , the Company expects to recognize the long term performance obligations in 2020. Advertising Costs The Company expenses the cost of advertising and promoting its services as incurred in the sales and marketing expense on the consolidated statement of operations. Such costs totaled approximately $17.4 million , $15.8 million , and $10.9 million for the years ended December 31, 2018 , 2017 and 2016 , respectively. Stock-based Compensation In accordance with ASC Topic 718 -10, "Stock Compensation", the Company measures stock based awards at fair value and recognizes compensation expense for all share-based payment awards made to its employees and directors, including employee stock options. The Company estimates the fair value of stock options granted using the Black-Scholes valuation model. This model requires the Company to make estimates and assumptions including, among other things, estimates regarding the length of time an employee will retain vested stock options before exercising them, the estimated volatility of its common stock price and the number of options that will be forfeited prior to vesting. The fair value is then recognized on a straight line basis over the requisite service period of the award, which is generally three to four years. Changes in these estimates and assumptions can materially affect the determination of the fair value of the stock-based compensation and consequently, the related amount recognized in the consolidated statement of operations. Deferred Rent The Company records rent expense on a straight-line basis over the term of the related lease. The difference between the rent expense recognized for financial reporting purposes and the actual payments made in accordance with the lease agreement is recognized as deferred rent liability included in other liabilities on the Company’s consolidated balance sheets. Income Taxes Income taxes are accounted for under the asset and liability method. Under this method, deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases and operating loss and tax credit carryforwards. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in results of operations in the period that the tax change occurs. In evaluating our ability to recover our deferred tax assets in the jurisdiction from which they arise, we consider all available positive and negative evidence, including scheduled reversals of deferred tax liabilities, projected future taxable income, tax-planning strategies, and results of recent operations. We include interest accrued on the underpayment of income taxes in interest expense and penalties, if any, related to unrecognized tax benefits in general and administrative expenses. Valuation allowances are established, when necessary, to reduce deferred tax assets to the amount expected to be realized Comprehensive Loss In accordance with ASC 220, "Comprehensive Income", the Company reports by major components and as a single total, the change in its net assets during the period from non-owner sources. Comprehensive income (loss) consists of net income (loss), and accumulated other comprehensive income (loss), which includes certain changes in equity that are excluded from net income (loss). The Company’s comprehensive loss for all periods presented is related to the effect of foreign currency translation. Recently Issued Accounting Standards In August 2018, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update ("ASU") No. 2018-15 "Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract; Disclosures for Implementation Costs Incurred for Internal-Use Software and Cloud Computing Arrangements" (“ASU 2018-15”). This standard aligns the accounting for implementation costs incurred in a hosting arrangement that is a service contract with the accounting for implementation costs incurred to develop or obtain internal-use software under Accounting Standards Codification ("ASC") 350-40, in order to determine which costs to capitalize and recognize as an asset.

Net Loss per Share

Net Loss per Share	12 Months Ended
	Dec. 31, 2018
Earnings Per Share [Abstract]
Net Loss per Share	Net Loss per Share The Company calculates earnings per share (“EPS”) in accordance with the provisions of ASC 260-10 and the guidance of SEC Staff Accounting Bulletin (“SAB”) No. 98. Under ASC 260-10, basic EPS excludes dilution for common stock equivalents and is computed by dividing net income or loss attributable to common shareholders by the weighted average number of common shares outstanding for the period. All options, warrants or other potentially dilutive instruments issued for nominal consideration are required to be included in the calculation of basic and diluted net income attributable to common stockholders. Diluted EPS is calculated using the treasury stock method and reflects the potential dilution that could occur if securities or other contracts to issue common stock were exercised or converted into common stock and resulted in the issuance of common stock. Diluted net loss per common share for the year ended December 31, 2018 does not include the effect of options to purchase 8,957,672 shares of common stock awards as the effect of their inclusion is anti-dilutive. Diluted net income per common share for the year ended December 31, 2017 does not include the effect of options to purchase 8,831,798 shares of common stock awards as the effect of their inclusion is anti-dilutive. Diluted net income per common share for the year ended December 31, 2016 does not include the effect of options to purchase 8,956,932 shares of common stock awards as the effect of their inclusion is anti-dilutive. A reconciliation of shares used in calculating basic and diluted earnings per share follows: Year Ended December 31, 2018 2017 2016 Basic 59,203,400 56,358,017 56,063,777 Effect of assumed exercised options — — — Diluted 59,203,400 56,358,017 56,063,777

Segment Information

Segment Information	12 Months Ended
	Dec. 31, 2018
Segment Reporting [Abstract]
Segment Information	Segment Information The Company accounts for its segment information in accordance with the provisions of ASC 280-10, “Segment Reporting.” ASC 280-10 establishes annual and interim reporting standards for operating segments of a company. ASC 280-10 requires disclosures of selected segment-related financial information about products, major customers, and geographic areas based on the Company’s internal accounting methods. The Company is organized into two operating segments for purposes of making operating decisions and assessing performance. The Business segment enables brands to leverage LiveEngage’s sophisticated intelligence engine to connect with consumers through an integrated suite of mobile and online business messaging technologies. The Consumer segment facilitates online transactions between independent service providers (“Experts”) and individual consumers (“Users”) seeking information and knowledge for a fee via mobile and online messaging. Both segments currently generate their revenue primarily in the United States. The chief operating decision maker, who is the chief executive officer, evaluates performance, makes operating decisions, and allocates resources based on the operating income of each segment. The reporting segments follow the same accounting polices used in the preparation of the Company’s consolidated financial statements which are described in the summary of significant accounting policies. The Company allocates cost of revenue, sales and marketing and amortization of purchased intangibles to the segments, but it does not allocate product development expenses, general and administrative expenses, restructuring costs and income tax expense because management does not use this information to measure performance of the operating segments. There are currently no inter-segment sales. Summarized financial information by segment for the year ended December 31, 2018 , based on the Company’s internal financial reporting system utilized by the Company’s chief operating decision maker, follows (amounts in thousands): Business Consumer Corporate Consolidated Revenue: Hosted services – Business $ 197,474 $ — $ — $ 197,474 Hosted services – Consumer — 19,553 — 19,553 Professional services 32,811 — — 32,811 Total revenue 230,285 19,553 — 249,838 Cost of revenue 58,420 4,059 — 62,479 Sales and marketing 94,339 9,005 — 103,344 Amortization of purchased intangibles 1,670 — — 1,670 Unallocated corporate expenses — — 106,048 106,048 Operating income (loss) $ 75,856 $ 6,489 $ (106,048 ) $ (23,703 ) Summarized financial information by segment for the year ended December 31, 2017 , based on the Company’s internal financial reporting system utilized by the Company’s chief operating decision maker, follows (amounts in thousands): Business Consumer Corporate Consolidated Revenue: Hosted services – Business $ 178,686 $ — $ — $ 178,686 Hosted services – Consumer — 17,450 — 17,450 Professional services 22,740 — — 22,740 Total revenue 201,426 17,450 — 218,876 Cost of revenue 54,600 3,605 — 58,205 Sales and marketing 82,420 8,485 — 90,905 Amortization of purchased intangibles 1,840 — — 1,840 Unallocated corporate expenses — — 85,752 85,752 Operating income (loss) $ 62,566 $ 5,360 $ (85,752 ) $ (17,826 ) Summarized financial information by segment for the year ended December 31, 2016 , based on the Company’s internal financial reporting system utilized by the Company’s chief operating decision maker, follows (amounts in thousands): Business Consumer Corporate Consolidated Revenue: Hosted services – Business $ 183,551 $ — $ — $ 183,551 Hosted services – Consumer — 16,258 — 16,258 Professional services 22,970 — — 22,970 Total revenue 206,521 16,258 — 222,779 Cost of revenue 60,352 2,809 — 63,161 Sales and marketing 82,063 7,466 — 89,529 Amortization of purchased intangibles 3,885 — — 3,885 Unallocated corporate expenses — — 85,613 85,613 Operating income (loss) $ 60,221 $ 5,983 $ (85,613 ) $ (19,409 ) Geographic Information The Company is domiciled in the United States and has international operations in the United Kingdom, Asia-Pacific, Latin America and Western Europe, particularly France and Germany. The following table presents the Company's long-lived assets by geographic region for the periods presented (amounts in thousands): December 31, 2018 2017 United States $ 122,019 $ 93,845 Israel 13,598 13,940 Australia 8,970 9,496 Netherlands 7,426 7,495 Other (1) 3,130 2,711 Total long-lived assets $ 155,143 $ 127,487 (1) United Kingdom, Germany, Japan, France, and Italy

Property and Equipment

Property and Equipment	12 Months Ended
	Dec. 31, 2018
Property, Plant and Equipment [Abstract]
Property and Equipment	Property and Equipment The following table presents the detail of property and equipment for the periods presented (amounts in thousands): December 31, 2018 2017 Computer equipment and software $ 79,161 $ 92,079 Furniture, equipment and building improvements 14,132 15,355 Internal-use software development costs 19,240 8,736 112,533 116,170 Less: accumulated depreciation (68,798 ) (81,465 ) Total $ 43,735 $ 34,705 In accordance with its policy, the Company reviews the estimated useful lives of its fixed assets on an ongoing basis. As of December 31, 2018, there was approximately $7.8 million of internal-use software development costs related to projects currently still in development, therefore, are not yet subject to amortization. Aggregate depreciation expense for property and equipment was $14.2 million , $12.4 million and $12.0 million for the years ended December 31, 2018 , 2017 , and 2016 , respectively.

Goodwill and Intangible Assets

Goodwill and Intangible Assets	12 Months Ended
	Dec. 31, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Goodwill and Intangible Assets	Goodwill and Intangible Assets Goodwill The changes in the carrying amount of goodwill for the year ended December 31, 2018 are as follows (amounts in thousands): Business Consumer Total Balance as of December 31, 2017 $ 72,507 $ 8,024 $ 80,531 Adjustments to goodwill: Acquisitions 14,606 — 14,606 Foreign exchange adjustments (106 ) — (106 ) Balance as of December 31, 2018 $ 87,007 $ 8,024 $ 95,031 The changes in the carrying amount of goodwill for the year ended December 31, 2017 are as follows (amounts in thousands): Business Consumer Total Balance as of December 31, 2016 $ 72,221 $ 8,024 $ 80,245 Adjustments to goodwill: Foreign exchange adjustments 286 — 286 Balance as of December 31, 2017 $ 72,507 $ 8,024 $ 80,531 The total accumulated goodwill impairment charges are $23.5 million through December 31, 2018 . No impairment was recognized for the years ended December 31, 2018 , 2017 , and 2016 . Intangible Assets Intangible assets are summarized as follows (see Note 8) (amounts in thousands): December 31, 2018 Gross Carrying Amount Accumulated Amortization Net Carrying Amount Weighted Average Amortization Period Amortizing intangible assets: Technology $ 30,447 $ (23,615 ) $ 6,832 5.3 years Customer relationships 17,219 (11,786 ) 5,433 8.4 years Trade names 1,286 (1,286 ) — 2.1 years Non-compete agreements 1,436 (1,436 ) — 2.3 years Patents 2,074 (534 ) 1,540 12.4 years Other 262 (235 ) 27 2.7 years Total $ 52,724 $ (38,892 ) $ 13,832 December 31, 2017 Gross Carrying Amount Accumulated Amortization Net Carrying Amount Weighted Average Amortization Period Amortizing intangible assets: Technology $ 27,882 $ (22,197 ) $ 5,685 5.3 years Customer relationships 15,978 (10,457 ) 5,521 8.0 years Trade names 1,289 (1,283 ) 6 2.1 years Non-compete agreements 1,439 (1,439 ) — 2.3 years Patents 1,620 (493 ) 1,127 13.1 years Other 262 (235 ) 27 2.7 years Total $ 48,470 $ (36,104 ) $ 12,366 Amortization expense is calculated over the estimated useful life of the asset. Aggregate amortization expense for intangible assets was $ 2.8 million , $4.7 million and $6.7 million for the years ended December 31, 2018 , 2017 and 2016 , respectively. For the years ended December 31, 2018 , 2017 and 2016 , a portion of this amortization is included in cost of revenue. Estimated amortization expense for the next five years are as follows (amounts in thousands): Estimated Amortization Expense 2019 $ 2,901 2020 2,708 2021 2,498 2022 2,143 2023 902 Thereafter 2,680 Total $ 13,832

Accrued Liabilities and Other C

Accrued Liabilities and Other Current Liabilities	12 Months Ended
	Dec. 31, 2018
Payables and Accruals [Abstract]
Accrued Liabilities and Other Current Liabilities	Accrued Liabilities and Other Current Liabilities The following table presents the detail of accrued liabilities and other current liabilities for the periods presented (amounts in thousands): December 31, 2018 2017 Payroll and other employee related costs $ 19,014 $ 16,431 Professional services, consulting and other vendor fees 17,461 15,674 Unrecognized tax benefits 1,913 4,924 Sales commissions 6,239 5,259 Contingent earn-out (Note 8) 2,372 — Restructuring 977 2,338 Other 2,686 3,385 Total $ 50,662 $ 48,011

Acquisitions

Acquisitions	12 Months Ended
	Dec. 31, 2018
Business Combinations [Abstract]
Acquisitions	Acquisitions AdvantageTec Inc. In October 2018, the Company entered into a stock purchase agreement to acquire the outstanding equity interest of AdvantageTec, Inc. (“AdvantageTec”), a leading provider of texting solutions for service departments of automotive dealerships that helps enable Conversational Commerce across the entire dealership, including both front end/variable operations (new and used vehicle sales) and back end/fixed operations (parts and services). The purchase agreement was for total consideration of approximately $11.2 million , which includes approximately $6.0 million in cash, approximately $4.3 million in shares of common stock, and approximately $0.9 million of potential earn-out consideration in cash and shares of common stock. The earn-out is contingent upon achieving certain targeted financial, strategic and integration objectives and milestones and is included as part of the purchase price. The purchase price allocation resulted in approximately $9.1 million of goodwill and approximately $2.2 million of intangible assets. The goodwill will not be deductible for tax purposes. The intangible assets are being amortized over their expected period of benefit. A deferred tax liability for the identified intangibles has been recorded. There was approximately $0.6 million of acquisition costs, which is included in general and administrative expenses in the Company's consolidated statements of operations and deferred tax liability of $0.5 million . The net book value of acquired assets and liabilities resulted in a net liability $0.1 million . AdvtangeTec, Inc. enhances the Company’s messaging platform available for the automotive industry and will be included in the Company's business segment. The results of this acquisition were not significant to the results of operations for the year ended December 31, 2018. Conversable, Inc. In September 2018, the Company acquired the employees and technology assets of Conversable, Inc. a SaaS based Artificial Intelligence powered conversational platform, headquartered in Austin, Texas, for an aggregated estimated purchase price of $5.7 million . The estimated purchase price consisted of $1.3 million in cash, approximately $2.9 million in shares of common stock of the Company, and a potential earn-out consideration of $1.5 million in cash, which is based on achieving certain targeted financial, strategic, and integration objectives. This transaction was accounted for under the purchase method of accounting and was based upon the estimated fair value of Conversable, Inc.'s net tangible and identifiable intangible assets as of the date of acquisition. The purchase price allocation resulted in approximately $5.5 million of goodwill and approximately $0.5 million of intangible assets. The goodwill will be deductible for tax purposes. The intangible assets are being amortized over their expected period of benefit. The allocation of the purchase price to net book value of acquired assets and liabilities resulted in a net liability $0.3 million , which includes accounts receivable, property and equipment, accrued expenses, and deferred revenue. Conversable Inc.’s capabilities will accelerate the ongoing expansion of the Company's Conversational Commerce solutions and enhance the Company’s ability to deliver proactive and personalized content and services when and where the customer needs it, helping consumers find immediate service through messaging. Conversable, Inc will be included in the Company's business segment. The results of this acquisition were not significant to the results of operations for the year ended December 31, 2018. BotCentral, Inc. In January 2018, the Company acquired the employees and technology assets of BotCentral, Inc., a Silicon Valley based startup, for an approximate purchase price of $1.0 million in common stock of the Company. The Company incurred an additional $0.2 million related to acquisition costs. This transaction was accounted for as an asset purchase. The aggregate amount of approximately $1.2 million is included in intangibles on the Company's consolidated balance sheet. With the team's expertise and knowledge of the LiveEngage platform, the team is bringing valuable insight for the Company's customers and partners, and enabling the company to more rapidly optimize its bot deployment capabilities, and grow the ecosystem. BotCentral, Inc will be included in the Company's business segment. The results of this acquisition were not significant to the results of operations for the year ended December 31, 2018.

Fair Value Measurements

Fair Value Measurements	12 Months Ended
	Dec. 31, 2018
Fair Value Disclosures [Abstract]
Fair Value Measurements	Fair Value Measurements The Company measures its cash equivalents at fair value based on an expected exit price as defined by the authoritative guidance on fair value measurements, which represents the amount that would be received on the sale of an asset or paid to transfer a liability, as the case may be, in an orderly transaction between market participants. As such, fair value may be based on assumptions that market participants would use in pricing an asset or liability. The authoritative guidance on fair value measurements establishes a consistent framework for measuring fair value on either a recurring or nonrecurring basis whereby inputs, used in valuation techniques, are assigned a hierarchical level. The following are the hierarchical levels of inputs to measure fair value: • Level 1: Observable inputs that reflect quoted prices (unadjusted) for identical assets or liabilities in active markets. • Level 2: Inputs reflect: quoted prices for identical assets or liabilities in markets that are not active; quoted prices for similar assets or liabilities in active markets; inputs other than quoted prices that are observable for the assets or liabilities; or inputs that are derived principally from or corroborated by observable market data by correlation or other means. • Level 3: Unobservable inputs reflecting the Company’s assumptions incorporated in valuation techniques used to determine fair value. These assumptions are required to be consistent with market participant assumptions that are reasonably available. Financial Assets and Liabilities The carrying amount of cash, accounts receivable, and accounts payable approximate their fair value due to their short-term nature. The Company's assets and liabilities that are measured at fair value on a recurring basis, by level, within the fair value hierarchy as of December 31, 2018 and December 31, 2017 , are summarized as follows (amounts in thousands). The Company did not have any restricted cash balance as of December 31, 2018 . The Company's restricted cash balance of $1.5 million at December 31, 2017 is not held in a money market account and is not included in the following table. December 31, 2018 December 31, 2017 Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Total Assets: Cash equivalents: Money market funds $ 2,828 $ — $ — $ 2,828 $ 2,806 $ — $ — $ 2,806 Foreign currency derivative contracts — — — — — 65 — 65 Total assets $ 2,828 $ — $ — $ 2,828 $ 2,806 $ 65 $ — $ 2,871 Liabilities: Contingent earn-out $ — $ — $ 2,372 $ 2,372 $ — $ — $ — $ — Foreign currency derivative contracts — — — — — 2 — 2 Total liabilities $ — $ — $ 2,372 $ 2,372 $ — $ 2 $ — $ 2 In determining fair value, the Company utilizes valuation techniques that maximize the use of observable inputs and minimize the use of unobservable inputs to the extent possible as well as considers counterparty credit risk in its assessment of fair value. Observable or market inputs reflect market data obtained from independent sources, while unobservable inputs reflect the Company's assumptions based on the best information available. The Company's money market funds are measured at fair value on a recurring basis based on quoted market prices in active markets and are classified as level 1 within the fair value hierarchy. The Company's contingent earn-out liability and foreign currency derivative contracts are measured at fair value on a recurring basis and are classified as level 3 and level 2, respectively, within the fair value hierarchy. On a nonrecurring basis, the Company uses fair value measures when analyzing asset impairment. Long-lived tangible assets are reviewed for impairment whenever events or changes in circumstances indicate that the carrying amount of an asset may not be recoverable. If it is determined such indicators are present and the review indicates that the assets will not be fully recoverable, based on undiscounted estimated cash flows over the remaining amortization periods, their carrying values are reduced to estimated fair value. The Company uses an income approach and inputs that constitute level 3. During the third quarter of each year, the Company evaluates goodwill for impairment at the reporting unit level. The Company uses qualitative factors in accordance with ASU No. 2011-08 to determine whether it is "more likely than not" that the fair value of a reporting unit is less than its carrying amount as a basis for determining whether it is necessary to perform the two-step goodwill impairment test. This measurement is classified based on level 3 input. During the year ended December 31, 2017 , the final payment of $0.2 million was made in connection with contingent earnout recorded as a result of the acquisition of Synchronite based on the fulfillment of a complete product integration and a minimum number of “Co-Browse” interactions per month. During the year ended December 31, 2018 , the contingent earnouts totaling $2.4 million were added as a result of the acquisitions of Conversable, Inc and AdvantageTec, Inc. The earn-outs are contingent upon achieving certain targeted financial, strategic and integration objectives and milestones relating. The changes in fair value of the Level 3 liabilities are as follows (amounts in thousands): Contingent Earn-Out December 31, 2018 2017 Balance, Beginning of year $ — $ 210 Conversable, Inc. addition (see Note 7) 1,496 — AdvantageTec, Inc. addition (see Note 7) 876 — Cash payment — (210 ) Balance, End of year $ 2,372 $ — Derivative Financial Instruments The Company is exposed to foreign exchange risks that are managed in part by using derivative financial instruments. The Company enters into foreign currency forward contracts related to risks associated with foreign operations. The Company does not use derivatives for trading purposes and at December 31, 2018 has no derivatives that are designated as fair value hedges. Derivatives are recorded at their estimated fair values based upon Level 2 inputs. Derivatives designated and effective as cash flow hedges are reported as a component of other comprehensive income and reclassified to earnings in the same periods in which the hedged transactions impact earnings. Gains and losses related to derivatives not meeting the requirements of hedge accounting and the portion of derivatives related to hedge ineffectiveness are recognized in current earnings. As of December 31, 2018 , the Company is not party to any foreign currency forward contracts and does not have any restricted cash balance. At December 31, 2017 , in accordance with the foreign currency forward contracts, the Company was required to pledge cash as collateral security to be maintained at an Israeli bank. The collateral security would remain in control of the bank, to be available in order to satisfy outstanding obligations under the foreign currency forward contracts. Accordingly, the Company had cash at an Israeli bank of approximately $1.5 million at December 31, 2017 , which was recorded as cash held as collateral in current assets. The following summarizes certain information regarding the Company’s outstanding foreign currency derivative contracts related primarily to intercompany receivables and payables for the periods presented (in thousands): December 31, 2018 December 31, 2017 Notional amount of foreign currency derivative contracts $ — $ 2,866 Fair value of foreign currency derivatives contracts — 63 The fair value of the Company’s derivative instruments is summarized below (in thousands): Fair Value of Derivative Instruments Balance Sheet Location December 31, 2018 December 31, 2017 Derivative Assets Derivatives not designated as hedging instruments: Foreign currency derivatives contracts Prepaid expenses and other current assets $ — $ 65 Derivative Liabilities Derivatives not designated as hedging instruments: Foreign currency derivatives Accrued expenses and other liabilities $ — $ 2 The following summarizes certain information regarding the Company’s derivatives that are not designated or are not effective as hedges (in thousands): Gain (losses) on Derivative Instruments Recognized in Income Statement Income Statement Location December 31, 2018 December 31, 2017 Foreign currency derivatives contracts Other (Expense) Income, net $ (50 ) $ 236

Commitments and Contingencies

Commitments and Contingencies	12 Months Ended
	Dec. 31, 2018
Commitments and Contingencies Disclosure [Abstract]
Commitments and Contingencies	ommitments and Contingencies Contractual Obligations The Company leases facilities and certain equipment under agreements accounted for as operating leases. These leases generally require the Company to pay all executory costs such as maintenance and insurance. Rental expense for operating leases for the years ended December 31, 2018 , 2017 , and 2016 was approximately $10.9 million , $9.9 million and $10.0 million , respectively. Future minimum lease payments under non-cancellable operating leases (with an initial or remaining lease terms in excess of one year) are as follows (amounts in thousands): Year Ending December 31, Operating Leases 2019 $ 8,488 2020 6,139 2021 5,477 2022 2,649 2023 883 Thereafter 61 Total minimum lease payments $ 23,697 Our other noncurrent liabilities in the consolidated balance sheet include unrecognized tax benefits. As of December 31, 2018, we had gross unrecognized tax benefits of $1.9 million. At this time, we are unable to make a reasonably reliable estimate of the timing of payments in individual years in connection with these tax liabilities; therefore, such amounts are not included in the above contractual obligation table. Employee Benefit Plans The Company has a 401(k) defined contribution plan covering all eligible employees. The Company provides for employer matching contributions equal to 50% of employee contributions, up to the lesser of 5% of eligible compensation or $6,000 . Matching contributions are deposited into the employees 401(k) account and are subject to 5 year graded vesting. Total Company matching contributions were $1.6 million , $1.4 million , and $1.3 million for the years ended for the year ended December 31, 2018 , 2017 and 2016 , respectively. Indemnifications The Company enters into service and license agreements in its ordinary course of business. Pursuant to some of these agreements, the Company agrees to indemnify certain customers from and against certain types of claims and losses suffered or incurred by them as a result of using the Company’s products. The Company also has agreements whereby its executive officers and directors are indemnified for certain events or occurrences while the officer or director is, or was serving, at the Company’s request in such capacity. The maximum potential amount of future payments the Company could be required to make under these indemnification agreements is unlimited; however, the Company has a directors and officers insurance policy that reduces its exposure and enables the Company to recover a portion of any future amounts paid. As a result of its insurance policy coverage, the Company believes the estimated fair value of these indemnification agreements is minimal. Currently, the Company has no liabilities recorded for these agreements as of December 31, 2018 . Letters of Credit As of December 31, 2018 , the Company has a $1.8 million letter of credit outstanding substantially in favor of a certain landlord for office space. In addition, the Company has a letter of credit totaling $0.1 million as a security deposit for the due performance by the Company of the terms and conditions of a supply contract. There were no draws against these letters of credit during the year ended December 31, 2018 .

Stockholders' Equity

Stockholders' Equity	12 Months Ended
	Dec. 31, 2018
Equity [Abstract]
Stockholders' Equity	Stockholders' Equity Common Stock At December 31, 2018 , there were 100,000,000 shares of common stock authorized, and 63,676,229 shares issued and outstanding. As of December 31, 2017 , there were 100,000,000 shares of common stock authorized, and 59,663,969 shares issued and outstanding. The par value for common shares is $ 0.001 . Preferred Stock As of December 31, 2018 and 2017 , there were 5,000,000 shares of preferred stock authorized, and zero shares issued and outstanding. The par value for preferred shares is $ 0.001 . Stock Repurchase Program From 2012 through 2018, the Company had a stock repurchase program in place pursuant to which the Company was authorized to repurchase shares of its common stock, in the open market or privately negotiated transactions, at times and prices considered appropriate by the Board of Directors depending upon prevailing market conditions and other corporate considerations. The timing and actual number of shares repurchased depend on a variety of factors including the timing of open trading windows, price, corporate and regulatory requirements and other market conditions. The program was discontinued at the end of 2018. The Company may or may not enter into a new stock repurchase program in the future. Stock-Based Compensation The Company follows FASB ASC 718-10, “Stock Compensation,” which addresses the accounting for transactions in which an entity exchanges its equity instruments for goods or services, with a primary focus on transactions in which an entity obtains employee services in share-based payment transactions. ASC 718-10 requires measurement of the cost of employee services received in exchange for an award of equity instruments based on the grant-date fair value of the award. Incremental compensation costs arising from subsequent modifications of awards after the grant date must be recognized. The per share weighted average fair value of stock options granted during the years ended December 31, 2018 , 2017 and 2016 was $ 6.60 , $ 4.25 , and $ 3.10 , respectively. The fair value of each option grant is estimated on the date of grant using the Black-Scholes option-pricing model with the following weighted average assumptions for the years ended December 31, 2018 , 2017 and 2016 : December 31, 2018 2017 2016 Dividend yield —% —% —% Risk-free interest rate 2.5% – 3.1% 1.7% – 2.1% 1.0% – 1.8% Expected life (in years) 5.0 5.0 5.0 Historical volatility 43.5% – 48.4% 46.6% – 48.1% 46.8% – 48.2% A description of the methods used in the significant assumptions used to estimate the fair value of stock-based-based compensation awards follows: Dividend yield – The Company uses 0% as it has never issued dividends and does not anticipate issuing dividends in the near term. Risk-free interest rate – The Company uses the market yield on U.S. Treasury securities at five years with constant maturity, representing the current expected life of stock options in years. Expected life – The Company uses historical data to estimate the expected life of a stock option. Historical volatility – The Company uses a trailing five year from grant date to determine volatility. Stock Option Plans During 1998, the Company established the Stock Option and Restricted Stock Purchase Plan (the “1998 Plan”). Under the 1998 Plan, the Board of Directors could issue incentive stock options or nonqualified stock options to purchase up to 5,850,000 shares of common stock. The 2000 Stock Incentive Plan (the “2000 Plan”) succeeded the 1998 Plan. Under the 2000 Plan, the options which had been outstanding under the 1998 Plan were incorporated in the 2000 Plan increasing the number of shares available for issuance under the plan by approximately 4,150,000 , thereby reserving for issuance 10,000,000 shares of common stock in the aggregate. The Company established the 2009 Stock Incentive Plan (as amended and restated, the “2009 Plan”) as a successor to the 2000 Plan. Under the 2009 Plan, the options which had been outstanding under the 2000 Plan were incorporated into the 2009 Plan and the Company increased the number of shares available for issuance under the plan by 6,000,000 . The Company amended the 2009 Stock Incentive Plan (the “Amended 2009 Plan”) effective June 7, 2012. The Amended 2009 Plan increased the number of shares authorized for issuance under the plan by an additional 4,250,000 . On June 2, 2017, the Company's Board of Directors amended and restated the Amended 2009 Plan effective April 30, 2017. The amended and restated plan increased the number of shares authorized for issuance under the plan by an additional 4,000,000 , thereby reserving for issuance 23,817,744 shares of common stock in the aggregate. Options to acquire common stock granted thereunder have 10 -year terms. As of December 31, 2018 , approximately 2.7 million shares of common stock were remaining authorized for issuance under the 2009 Plan (taking into account all option exercises through December 31, 2018 ). Employee Stock Purchase Plan In June 2010, the Company's stockholders approved the 2010 Employee Stock Purchase Plan with 1,000,000 shares of common stock initially reserved for issuance. Subject to stockholder approval, which was obtained on June 2, 2017, the Company's Board of Directors amended and restated the 2010 Employee Stock Purchase Plan effective April 30, 2017. The amended and restated plan increased the number of shares authorized for issuance under the plan by an additional 1,000,000 , thereby reserving for issuance 2,000,000 shares of common stock in the aggregate. As of December 31, 2018 , approximately 0.9 million shares of common stock were reserved for issuance under the Employee Stock Purchase Plan (taking into account all share purchases through December 31, 2018 ). Inducement Plan During January 2018, the Company established the Inducement Plan (the “2018 Plan”). Under the 2018 Plan, the Board of Directors can issue incentive stock options or nonqualified stock options or other equity-based awards in respect of up to 1,500,000 shares of common stock. On April 25, 2018, the Company's Board of Directors amended and restated the 2018 Plan (the "Amended 2018 Plan"). The Amended 2018 Plan increased the number of shares authorized for issuance under the plan by an additional 500,000 shares, thereby reserving for issuance 2,000,000 shares of common stock in the aggregate. As of December 31, 2018 , approximately 0.1 million shares of common stock were reserved for issuance under the Amended 2018 Plan (taking into account all option grants and other equity award settlements through December 31, 2018 ). Stock Option Activity A summary of the Company’s stock option activity and weighted average exercise prices follows: Stock Option Activity Weighted Average Remaining Contractual Term (in years) Aggregate Intrinsic Value (in thousands) Options (in thousands) Weighted Balance outstanding at December 31, 2015 9,144 $ 11.05 Granted 635 7.32 Exercised (325 ) 5.66 Cancelled or expired (1,685 ) 11.49 Balance outstanding at December 31, 2016 7,769 $ 10.88 6.05 $ 2,641 Options vested and expected to vest 7,348 $ 11.00 5.90 $ 2,529 Options exercisable at December 31, 2016 5,580 $ 11.31 5.27 $ 2,347 Balance outstanding at December 31, 2016 7,769 $ 10.88 Granted 2,042 9.87 Exercised (854 ) 8.80 Cancelled or expired (998 ) 11.98 Balance outstanding at December 31, 2017 7,959 $ 10.71 5.85 $ 14,881 Options vested and expected to vest 7,163 $ 10.75 5.49 $ 13,197 Options exercisable at December 31, 2017 5,163 $ 11.17 4.50 $ 8,648 Balance outstanding at December 31, 2017 7,959 $ 10.71 Granted 2,033 15.00 Exercised (3,120 ) 10.70 Cancelled or expired (606 ) 10.03 Balance outstanding at December 31, 2018 6,266 $ 12.13 6.55 $ 43,348 Options vested and expected to vest 5,550 $ 11.89 6.28 $ 39,521 Options exercisable at December 31, 2018 3,278 $ 11.12 4.64 $ 25,367 The total fair value of stock options exercised during the years ended December 31, 2018 and 2017 was approximately $16.1 million and $3.7 million , respectively. As of December 31, 2018 , there was approximately $14.4 million of total unrecognized compensation cost related to nonvested share-based compensation arrangements. That cost is expected to be recognized over a weighted average period of approximately 2.7 years. The following table summarizes information about outstanding and vested stock options as of December 31, 2018 : Options Outstanding Options Exercisable Range of Exercise Prices Number of Shares Outstanding (in thousands) Weighted-Average Remaining Contractual Life (Years) Weighted-Average Exercise Price Number of Shares (in thousands) Weighted-Average Exercise Price $1.79 - $7.60 1,081 6.37 $ 7.03 570 $ 6.70 $7.95 - $9.55 635 5.90 9.20 488 9.18 $9.90 - $10.13 640 5.33 10.09 636 10.09 $10.31 - $11.96 660 6.77 11.26 388 11.00 $12.09 - $12.32 39 2.31 12.29 39 12.29 $12.45 - $12.45 930 9.13 12.45 — — $12.46 - $13.59 684 3.42 13.31 684 13.31 $14.30 - $15.96 678 7.22 14.73 146 14.97 $16.05 - $21.75 770 6.85 18.30 327 17.45 $22.04 - $23.50 149 9.56 22.91 — — 6,266 6.55 $ 12.13 3,278 $ 11.12 Restricted Stock Unit Activity A summary of the Company’s restricted stock units (“RSUs”) activity and weighted average exercise prices follows: Restricted Stock Unit Activity Number of Shares (in thousands) Weighted Average Grant Date Fair Value (Per Share) Aggregate Fair Value (in thousands) Balance outstanding at December 31, 2015 1,202 $ 10.31 $ 6,220 Awarded 571 6.32 — Released (394 ) 10.31 — Forfeited (191 ) 10.01 — Non-vested and outstanding at December 31, 2016 1,188 $ 8.44 $ 8,968 Balance outstanding at December 31, 2016 1,188 $ 8.44 $ 8,968 Awarded 332 8.16 — Released (363 ) 8.48 — Forfeited (284 ) 8.46 — Non-vested and outstanding at December 31, 2017 873 $ 8.29 $ 10,053 Balance outstanding at December 31, 2017 873 $ 8.29 $ 10,053 Awarded 2,568 17.02 — Released (361 ) 9.49 — Forfeited (390 ) 9.49 — Non-vested and outstanding at December 31, 2018 2,690 $ 15.81 $ 50,756 Expected to vest 1,875 $ 14.83 $ 35,357 RSUs granted to employees generally vest over a three to four -year period, or upon achievement of certain performance conditions. As of December 31, 2018 , total unrecognized compensation cost, adjusted for estimated forfeitures, related to nonvested RSUs was approximately $ 37.9 million and the weighted-average remaining vesting period was 2.8 years.

Income Taxes

Income Taxes	12 Months Ended
	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Income Taxes	Income Taxes Income taxes are accounted for under the asset and liability method. Under this method, deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases and operating loss and tax credit carryforwards. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. In assessing the realizability of deferred tax assets, management considers whether it is more likely than not that some portion or all of the deferred tax assets will be realized. The ultimate realization of deferred tax assets is dependent upon the generation of future taxable income during the periods in which those temporary differences are expected to become deductible. Management considers the scheduled reversal of deferred tax liabilities, projected future taxable income and tax planning strategies in making this assessment. The Company includes interest accrued on the underpayment of income taxes in interest expense and penalties, if any, related to unrecognized tax benefits in general and administrative expenses. The Company recorded a valuation allowance against its U.S. and Australia deferred tax asset as it considered its cumulative loss in recent years as a significant piece of negative evidence. Since valuation allowances are evaluated on a jurisdiction by jurisdiction basis, we believe that the deferred tax assets related to LivePerson UK, Kasamba Israel, LivePerson Japan and LivePerson LTD Israel are more likely than not to be realized as these jurisdictions have positive cumulative pre-tax book income after adjusting for permanent and onetime items. During the year ended December 31, 2018 , there was an increase in the valuation recorded of $6.9 million . Under Section 382 of the Internal Revenue Code of 1986, as amended (the "Code"), the Company’s use of its federal net operating loss (“NOL”) carryforwards may be limited if the Company experiences an ownership change, as defined in Section 382 of the Code. Such an annual limitation could result in the expiration of the NOL carryforwards before utilization. Corresponding provisions of state law may limit the Company’s ability to utilize NOL carryforwards for state tax purposes. As of December 31, 2018 , the Company had approximately $73.0 million of federal NOL carryforwards available to offset future taxable income. Included in this amount is $5.1 million of federal NOL carryovers from the Company’s acquisition of Proficient. Approximately $32.8 million of these federal NOL carryforwards were generated in taxable years ending on or before December 31, 2017 and will expire in various years through 2027. Federal NOL carryforwards generated in taxable years ending after December 31, 2017, do not expire, but generally may only offset up to 80% of federal taxable income earned in a taxable year. The domestic and foreign components of (loss) before provision for income taxes consist of the following (amounts in thousands): Year Ended December 31, 2018 2017 2016 United States $ (38,078 ) $ (25,585 ) $ (40,774 ) Israel 3,163 3,458 15,622 United Kingdom 3,690 2,087 2,345 Netherlands 3,235 1,568 3,104 Australia 686 (1,979 ) (2,774 ) Germany 2,900 2,424 2,085 Other (1) 230 337 453 $ (24,174 ) $ (17,690 ) $ (19,939 ) (1) Includes Japan, Italy, Singapore, Canada, and France No additional provision has been made for U.S. income taxes on the undistributed earnings of its Israeli subsidiary, LivePerson Ltd. (formerly HumanClick Ltd.), as such earnings have been taxed in the U.S. and accumulated earnings of the Company’s other foreign subsidiaries are immaterial through December 31, 2018 . The provision for income taxes consists of the following (amounts in thousands): Year Ended December 31, 2018 2017 2016 Current income taxes: U.S. Federal $ (1,932 ) $ — $ 1,829 State and local 67 47 27 Foreign 3,032 2,852 2,226 Total current income taxes 1,167 2,899 4,082 Deferred income taxes: U.S. Federal (295 ) (1,289 ) 841 State and local (28 ) (1,144 ) 99 Foreign 14 35 912 Total deferred income taxes (309 ) (2,398 ) 1,852 Total provision for income taxes $ 858 $ 501 $ 5,934 The difference between the total income taxes computed at the federal statutory rate and the provision for income taxes consists of the following: Year Ended December 31, 2018 2017 2016 Federal statutory rate 21.00 % 34.00 % 34.00 % State taxes, net of federal benefit 3.30 % 4.09 % 3.24 % Non-deductible expenses – ISO 4.73 % (0.78 )% (1.85 )% Global intangible low tax income inclusion (7.99 )% — % — % Non-deductible expenses – Other (2.58 )% (1.19 )% (0.88 )% Foreign tax rate differential (1.34 )% (1.97 )% 0.89 % Change in valuation allowance (28.91 )% 26.12 % (53.55 )% Stock based compensation 6.10 % — % — % Return to provision true-up adjustment — % — % (9.22 )% Effect of new tax legislation — % (56.84 )% — % Other 2.09 % (6.26 )% (2.42 )% Total provision for income taxes (3.60 )% (2.83 )% (29.79 )% The effects of temporary differences and federal NOL carryforwards that give rise to significant portions of federal deferred tax assets and deferred tax liabilities at December 31, 2018 and 2017 are presented below (amounts in thousands): Year Ended December 31, 2018 2017 Deferred tax assets: Net operating loss carryforwards $ 18,083 $ 8,093 Accounts payable and accrued expenses 4,024 4,429 Non-cash compensation 9,597 9,510 Intangibles amortization 5,691 5,513 Allowance for doubtful accounts 315 232 Total deferred tax assets 37,710 27,777 Less valuation allowance (30,185 ) (23,260 ) Deferred tax assets, net of valuation allowance 7,525 4,517 Deferred tax liabilities: Property and equipment (3,736 ) (2,010 ) Goodwill amortization and contingent earn-out adjustments (4,172 ) (2,669 ) Total deferred tax liabilities (7,908 ) (4,679 ) Net deferred tax liabilities $ (383 ) $ (162 ) We have income tax NOL carryforwards related to federal and Australian income tax carryforwards of $74.2 million and $5.3 million respectively. The Australian NOLs can be carried forward indefinitely. $39.2 million of the federal NOL can be carried forward indefinitely. $6.0 million will expire between 2023 and 2026, and $28.9 million will expire between 2036 and 2037. ASC Topic 740-10 clarifies the accounting for uncertainty in income taxes recognized in the financial statements in accordance with other provisions contained within this guidance. This topic prescribes a recognition threshold and a measurement attribute for the financial statement recognition and measurement of tax positions taken or expected to be taken in a tax return. For those benefits to be recognized, a tax position must be more likely than not to be sustained upon examination by the taxing authorities. The amount recognized is measured as the largest amount of benefit that is greater than 50% likely of being realized upon ultimate audit settlement. The Company had unrecognized tax benefits of $1.9 million and $4.9 million as of December 31, 2018 and 2017 , respectively. Accrued interest and penalties included in the Company's liability related to unrecognized tax benefits were immaterial at December 31, 2018 and 2017 . We believe that it is reasonably possible that approximately $0.5 million of current other remaining unrecognized tax benefits, each of which are individually insignificant, may be recognized by the end of 2019 as a result of a lapse of the statute of limitations. A reconciliation of the beginning and ending amount of unrecognized tax benefits is as follows (in thousands): Year Ended December 31, 2018 2017 Unrecognized tax benefits balance at January 1 $ 4,924 $ 4,240 Gross increase for tax positions of prior years — — Gross increase for tax positions of current years 405 684 Decrease due to expiration of statue (445 ) — Decrease due to settlement (2,963 ) — Gross unrecognized tax benefits at December 31 $ 1,921 $ 4,924 The tax years subject to examination by major tax jurisdictions include the years 2014 and forward for U.S states and New York City, the years 2015 and forward for U.S. Federal, and the years 2014 and forward for certain foreign jurisdictions. The decrease of $3.0 million was related to the settlement of an audit with the Israeli Tax Authority for the years 2013, 2014 and 2015 Tax Reform The Tax Cuts and Jobs Act makes broad and complex changes to the U.S. federal tax laws that affect fiscal 2017 , including, but not limited to requiring a one-time repatriation tax on certain unrepatriated earnings of foreign subsidiaries that is payable over eight years (the "Repatriation Tax"). The Tax Cuts and Jobs Act also establishes new tax laws that will affect 2018 and later years, including, but not limited to, a reduction of the U.S. federal corporate income tax rate from a maximum of 34% to a flat rate of 21% , a general elimination of U.S. federal income taxes on certain dividends from foreign subsidiaries and a new provision designed to tax global intangible low-taxed income ("GILTI"). The legislation reduced the U.S. corporate tax rate from the current rate of 35% to 21% for tax years beginning after December 31, 2017 . Under the Tax Cuts and Jobs Act, the Company's $32.8 million in federal NOL carryforwards generated as of December 31, 2017 will continue to be carried forward for 20 years following their incurrence and are expected to be available to fully offset taxable income earned in future tax years. Federal net operating losses generated after 2017 will be carried forward indefinitely, but generally may only offset up to 80% of taxable income earned in a tax year. In the quarter ending December 31, 2017 , the Company revalued its deferred tax assets and liabilities due to these changes, including (a) revaluing the Company's federal net deferred tax assets before valuation allowance using the 21% tax rate, resulting in a decreased federal deferred tax provision of $10.1 million ; (b) revaluing the Company's federal valuation allowance using the 21% tax rate, including the impact of tax planning strategies, resulting in a federal deferred tax benefit to continuing operations of $12.6 million ; (c) recognizing a federal deferred tax benefit of $2.0 million for 80% of indefinite lived deferred tax liabilities, which are anticipated to be available as a source of taxable income upon reversal of deferred tax assets that would also have indefinite lives; and (d) recognizing a $1.2 million state deferred tax provision unaffected by the changes in the Tax Cuts and Jobs Act. The new legislation requires the Company to pay federal income tax on the unremitted earnings of its foreign subsidiaries though December 31, 2017 . Pursuant to SAB 118, the Company estimated the tax on unremitted earnings is zero due to an overall accumulated deficit in earnings and profits. As of the fourth quarter of 2018, the Company has finalized the preparation and analysis of the required information and has not changed from the estimate. The Tax Cuts and Jobs Act creates a new requirement that certain income earned by a foreign subsidiary must be included in the federal taxable income of the U.S. shareholder. This income (called Global Intangible Low-Taxed Income, or GILTI) is defined as the excess of a foreign subsidiaries income over a nominal return on fixed assets. The Company expects to be subject to this inclusion in future years. Under U.S. GAAP, the Company is allowed to make an accounting policy choice of either accounting for the effects of the GILTI inclusion as a current period expense, when incurred, or factoring such amounts into the Company’s measurement of its deferred taxes. The Company has elected to treat the effects of this provision as a period cost, and therefore, has not considered the impacts of GILTI on its deferred tax liabilities at December 31, 2018 . The Company's consolidated financial statements do not provide for any related tax liability on amounts that may be repatriated from foreign operations as the Company intends for these earnings to be indefinitely reinvested in operations outside the U.S. Accordingly, no deferred taxes have been provided for the basis difference in the foreign subsidiaries.

Legal Matters

Legal Matters	12 Months Ended
	Dec. 31, 2018
Loss Contingency, Information about Litigation Matters [Abstract]
Legal Matters	Legal Matters The Company previously filed an intellectual property suit against [24]7 Customer, Inc. in the Southern District of New York on March 6, 2014 seeking damages on the grounds that [24]7 reverse engineered and misappropriated the Company's technology to develop competing products and misused the Company's business information. On June 22, 2015 , [24]7 Customer, Inc. filed suit against the Company in the Northern District of California alleging patent infringement. On December 7, 2015 , [24]7 Customer Inc. filed a second patent infringement suit against the Company, also in the Northern District of California. On March 16, 2017, the New York case was voluntarily transferred and consolidated with the two California cases in the Northern District of California for all pre-trial purposes. Recent rulings by both the Court and the United States Patent Office in the Company's favor have invalidated the majority of [24]7 patents that were asserted in the patent cases. Trial for the Company's intellectual property and other claims asserted against [24]7 in the original litigation is not scheduled to allow for mediation. The Company believes the claims filed by [24]7 are entirely without merit and intends to defend them vigorously. The Company routinely assesses all of its litigation and threatened litigation as to the probability of ultimately incurring a liability, and records its best estimate of the ultimate loss in situations where the Company assesses the likelihood of loss as probable. From time to time, the Company is involved in or subject to legal, administrative and regulatory proceedings, claims, demands and investigations arising in the ordinary course of business, including direct claims brought by or against the Company with respect to intellectual property, contracts, employment and other matters, as well as claims brought against the Company’s customers for whom the Company has a contractual indemnification obligation. The Company accrues for a liability when it is both probable that a liability has been incurred and the amount of the loss can be reasonably estimated. Significant judgment is required in both the determination of probability and the determination as to whether a loss is reasonably estimable. In addition, in the event the Company determines that a loss is not probable, but is reasonably possible, and it becomes possible to develop what the Company believes to be a reasonable range of possible loss, then the Company will include disclosure related to such matter as appropriate and in compliance with ASC 450. The accruals or estimates, if any, resulting from the foregoing analysis, are reviewed at least quarterly and adjusted to reflect the impact of negotiations, settlements, rulings, advice of legal counsel and other information and events pertaining to a particular matter. To the extent there is a reasonable possibility that the losses could exceed the amounts already accrued, the Company will, as applicable, adjust the accrual in the period the determination is made, disclose an estimate of the additional loss or range of loss, indicate that the estimate is immaterial with respect to its financial statements as a whole or, if the amount of such adjustment cannot be reasonably estimated, disclose that an estimate cannot be made. From time to time, third parties assert claims against the Company regarding intellectual property rights, privacy issues and other matters arising in the ordinary course of business. Although the Company cannot be certain of the outcome of any litigation or the disposition of any claims, nor the amount of damages and exposure, if any, that the Company could incur, the Company currently believes that the final disposition of all existing matters will not have a material adverse effect on our business, results of operations, financial condition or cash flows. In addition, in the ordinary course of business, the Company is also subject to periodic threats of lawsuits, investigations and claims. Regardless of the outcome, litigation can have an adverse impact on the Company because of defense and settlement costs, diversion of management resources and other factors.

Restructuring Costs

Restructuring Costs	12 Months Ended
	Dec. 31, 2018
Restructuring and Related Activities [Abstract]
Restructuring Costs	Restructuring Costs The Company’s restructuring costs relate to wind-down and severance costs associated with re-prioritizing and reallocating resources to focus on areas showing high growth potential, as well as the termination of a large customer contract. In 2018 , we undertook a restructuring related primarily to a reorganization in order to promote continued globalization of our technology operations, drive improvements in quality assurance of existing products and creation of new add-on features to LiveEngage. The expense associated with this restructuring was approximately $4.5 million , $2.6 million , and $2.4 million during the years ended December 31, 2018 , 2017 , and 2016 , respectively, and is classified in the consolidated statements of operations as restructuring costs. The restructuring liability was approximately $1.0 million and $2.3 million as of December 31, 2018 and 2017 , respectively, and is classified as accrued expenses and other current liabilities on the consolidated balance sheets. The Company expects to incur additional restructuring costs of approximately $0.3 million through December 31, 2019. The following table presents the detail of the liability for the Company’s restructuring charges for the periods presented (amounts in thousands): December 31, 2018 December 31, 2017 Balance, Beginning of the year $ 2,338 $ 2,551 Severance and other associated costs 4,468 648 Cash payments (5,829 ) (2,807 ) Wind down costs of legacy platform — 1,946 Balance, End of year $ 977 $ 2,338 The following table presents the detail of expenses for the Company’s restructuring charges for the periods presented (amounts in thousands): December 31, 2018 December 31, 2017 December 31, 2016 Contract termination benefit $ — $ — $ (384 ) Severance and other associated costs 4,468 648 1,585 Wind down costs of legacy platform — 1,946 1,168 Total restructuring costs $ 4,468 $ 2,594 $ 2,369

Description of Business and S_2

Description of Business and Summary of Significant Accounting Policies (Policies)	12 Months Ended
	Dec. 31, 2018
Accounting Policies [Abstract]
Summary of Operations	LivePerson, Inc. (the “Company” or “LivePerson”) was incorporated in the State of Delaware in November 1995 and the LivePerson service was introduced in November 1998. In April 2000, the company completed an initial public offering and is currently traded on the NASDAQ Global Select Market and the Tel Aviv Stock Exchange. LivePerson is headquartered in New York City with U.S. offices in Alpharetta (Georgia), Austin (Texas), San Francisco (California) and Seattle (Washington), and international offices in Amsterdam (Netherlands), Berlin (Germany), London (United Kingdom), Mannheim (Germany), Melbourne (Australia), Milan (Italy), Paris (France), Ra'anana (Israel), Reading (United Kingdom), Tel Aviv (Israel), and Tokyo (Japan). LivePerson makes life easier by transforming how people communicate with brands. During the past decade, the consumer has made the mobile device the center of their digital lives, and they have made mobile messaging the center of communication with friends, family and peers. The Company’s technology enables consumers to connect with businesses through these same preferred conversational interfaces, including Facebook Messenger, WhatsApp, Apple Business Chat, Google Rich Business Messenger and Alexa. These messaging conversations harness human agents, bots and Artificial Intelligence (AI) to power convenient, personalized and content-rich journeys across the entire consumer lifecycle, from discovery and research, to sales, service and support, and even marketing and brick and mortar engagements. For example, consumers can look up product info like ratings, images and pricing, search for stores, see products in the store, schedule appointments, apply for credit, approve repairs, make purchases or payments - all without ever leaving the messaging channel. LivePerson calls these AI and human-assisted conversational experiences over messaging Conversational Commerce. LiveEngage, the Company’s enterprise-class, cloud-based platform, was designed for Conversational Commerce, enabling businesses to securely deploy messaging, coupled with bots and AI, at scale for brands with tens of millions of customers and many thousands of customer care agents. LiveEngage powers conversations across each of a brand’s primary digital channels, including mobile apps, mobile and desktop web browsers, short message service (SMS), social media and third-party consumer messaging platforms. Brands can also use LiveEngage to message consumers when they dial a 1-800 number instead of having them navigate interactive voice response systems (IVRs) and wait on hold. The robust, cloud-based suite of rich mobile messaging and real-time chat offerings features intelligent routing and capacity mapping, queue prioritization, customer sentiment, real-time analytics and reporting, content delivery, Payment Card Industry (PCI) compliance, cobrowsing and a sophisticated proactive targeting engine. With LiveEngage, agents can manage all conversations with consumers through a single console interface, regardless of which disparate messaging endpoints the consumers originate from: i.e., WhatsApp, Line, Apple Business Chat, IVR, or Google Home. An extensible application programming interface (API) stack facilitates a lower cost of ownership by facilitating robust integration into back-end systems, as well as enabling developers to build their own programs and services on top of the platform. More than three dozen APIs are available on LiveEngage. LiveEngage also features Maven, a robust AI engine that was custom designed for Conversational Commerce. Maven, announced in December 2018, puts the power of bot development, training and management into the hands of the contact center and its agents, the teams most familiar with how to structure sales and service conversations to drive successful outcomes. The platform enables what the Company calls “the tango” of humans, AI and bots, whereby human agents act as bot managers, overseeing AI-powered conversations and seamlessly stepping into the flow when a personal touch is needed. Through Maven Assist, agents become ultra-efficient, leveraging the AI engine to serve up relevant content, define next-best actions and take over repetitive transactional work, so that the agent can focus on relationship building. By seamlessly integrating LiveEngage with Maven, as well as third-party bots, the platform provides businesses with a comprehensive view of all AI-based and human-based conversations from a single console. Complementing LiveEngage are teams of technical, solutions and consulting professionals that have developed deep domain expertise in Conversational Commerce across industries and messaging endpoints. The Company is positioned as an authority in Conversational Commerce, publishing a proprietary Conversational Quotient™ Index that measures each customer across multiple key indicators to ascertain their level of conversational maturity. Each business is then benchmarked against industry peers to determine their relative progression. The Company has developed a Transformation Model that is introduced to existing and prospective customers to help guide them on their journeys from legacy and oftentimes inefficient legacy voice, email and chat solutions to modern conversational ones powered by messaging and AI. LivePerson’s products, coupled with our domain knowledge, industry expertise and professional services, have been proven to maximize the effectiveness of Conversational Commerce and deliver measurable return on investment. As a “cloud computing” or software-as-a-service (SaaS) provider, LivePerson provides solutions on a hosted basis. This model offers significant benefits over premise-based software, including lower up-front costs, faster implementation, lower total cost of ownership, scalability, cost predictability, and simplified upgrades. Organizations that adopt a fully-hosted, multi-tenant architecture that is maintained by LivePerson eliminate the majority of the time, server infrastructure costs, and IT resources required to implement, maintain, and support traditional on-premise software. Our consumer services offering is an online marketplace that connects independent service providers (Experts) who provide information and knowledge for a fee via mobile and online messaging with individual consumers (Users). Users seek assistance and advice in various categories including personal counseling and coaching, computers and programming, education and tutoring, spirituality and religion, and other topics.
Principles of Consolidation	Principles of Consolidation The consolidated financial statements reflect the operations of LivePerson and its wholly-owned subsidiaries. All significant intercompany balances and transactions have been eliminated in consolidation.
Reclassification	Reclassification For comparability, certain 2016 and 2017 amounts have been reclassified where appropriate, to conform to the financial presentation in 2018 .
Use of Estimates	Use of Estimates The preparation of the consolidated financial statements in accordance with accounting principles generally accepted in the United States of America (“GAAP”) requires the Company’s management to make a number of estimates and assumptions relating to the reported amounts of assets and liabilities, the disclosure of contingent assets and liabilities at the date of the consolidated financial statements and the reported amounts of revenue and expenses during the period. Significant items subject to such estimates and assumptions include revenue recognition, stock-based compensation, accounts receivable, the valuation of goodwill and intangible assets, income taxes and legal contingencies. Actual results could differ from those estimates.
Concentration of Credit Risk	Concentration of Credit Risk Financial instruments that potentially subject the Company to significant concentrations of credit risk consist primarily of cash and cash equivalents and accounts receivable which approximate fair value at December 31, 2018 because of the short-term nature of these instruments. The Company invests its cash and cash equivalents with financial institutions that it believes are of high quality, and the Company performs periodic evaluations of these instruments and the relative credit standings of the institutions with which it invests. At certain times, the Company’s cash balances with any one financial institution may exceed Federal Deposit Insurance Corporation insurance limits. The Company believes it mitigates its risk by depositing its cash balances with high credit, quality financial institutions. The Company performs ongoing credit evaluations of its customers’ financial condition (except for customers who purchase the LivePerson services by credit card via Internet download) and has established an allowance for doubtful accounts based upon factors surrounding the credit risk of customers, historical trends and other information. Concentration of credit risk is limited due to the Company’s large number of customers.
Foreign Currency Translation	Foreign Currency Translation The Company's operations are conducted in various countries around the world and the financial statements of its foreign subsidiaries are reported in the applicable foreign currencies (functional currencies). Financial information is translated from the applicable functional currency to the U.S. dollar (the reporting currency) for inclusion in the Company's consolidated financial statements. Income, expenses and cash flows are translated at weighted average exchange rates prevailing during the fiscal period, and assets and liabilities are translated at fiscal period-end exchange rates. Resulting translation adjustments are included as a component of accumulated other comprehensive income (loss) in stockholders' equity. Foreign exchange transaction gain or losses are included in Other Income, net in the accompanying consolidated statements of operations.
Cash and Cash Equivalents	Cash and Cash Equivalents The Company considers all highly liquid securities with original maturities of three months or less when acquired to be cash equivalents. Cash equivalents, which primarily consist of money market funds, are recorded at cost, which approximates fair value.
Accounts Receivable	Accounts Receivable Accounts receivable are recorded at the invoiced amount and do not bear interest. The allowance for doubtful accounts is the Company’s best estimate of the amount of probable credit losses in the Company’s existing accounts receivable. The Company determines the allowance based on historical write-off experience. The Company reviews its allowance for doubtful accounts monthly. Past due balances over 90 days and over a specified amount are reviewed individually for collectability. All other balances are reviewed on a pooled basis. Account balances are charged off against the allowance after all means of collection have been exhausted and the potential for recovery is considered remote. The Company does not have any off-balance sheet credit exposure related to its customers.
Property and Equipment	Property and Equipment Property and equipment are stated at cost, net of accumulated depreciation. Depreciation is calculated using the straight-line method over the estimated useful lives of the related assets, generally three to five years for equipment and software. Leasehold improvements are depreciated using the straight-line method over the shorter of the lease term or the estimated useful life of the asset.
Internal-Use Software Development Costs	Internal-Use Software Development Costs In accordance with the Financial Accounting Standards Board (“FASB”) Accounting Standards Codification (“ASC”) 350-40, "Internal-Use Software", the Company capitalizes its costs to develop its internal use software when preliminary development efforts are successfully completed, management has authorized and committed project funding, and it is probable that the project will be completed and the software will be used as intended. These costs are included in property and equipment in the Company's consolidated balance sheets and are amortized on a straight-line basis over the estimated useful life of the related asset, which approximates three years. Costs incurred prior to meeting these criteria, together with costs incurred for training and maintenance, are expensed as incurred.
Goodwill and Intangible Assets	Goodwill and Intangible Assets The Company records goodwill when the consideration paid in a business combination exceeds the fair value of the net tangible assets and the identified intangible assets acquired. Goodwill is not amortized, but instead is required to be tested for impairment annually and whenever events or changes in circumstances indicate that the carrying value of goodwill may exceed its fair value. The Company performs testing for impairment of goodwill in its third quarter, or as events occur or circumstances change that would more likely than not reduce the fair value of the Company’s reporting units below their carrying amounts. A qualitative assessment is first made to determine whether it is necessary to perform the two-step quantitative goodwill impairment test. This initial qualitative assessment includes, among other things, consideration of: (i) market capitalization of the Company, (ii) past, current and projected future earnings and equity; (iii) recent trends and market conditions; and (iv) valuation metrics involving similar companies that are publicly-traded and acquisitions of similar companies, if available. If this initial qualitative assessment indicates that it is more likely than not that impairment exists, a second analysis will be performed, involving a comparison between the estimated fair values of the Company’s reporting unit with its respective carrying amount including goodwill. If the carrying value exceeds estimated fair value, there is an indication of potential impairment, and a third analysis is performed to measure the amount of impairment. The third analysis involves calculating an implied fair value of goodwill by measuring the excess of the estimated fair value of the reporting unit over the aggregate estimated fair values of the individual assets less liabilities. If the carrying value of goodwill exceeds the implied fair value of goodwill, an impairment charge is recorded for the excess. Intangible assets with estimable useful lives are amortized over their respective estimated useful lives to their estimated residual values, and reviewed for impairment in accordance with ASC 360-10-35, “Accounting for Impairment or Disposal of Long-Lived Assets.” The Company evaluates for goodwill impairment annually at September 30 th and at the end of the third quarter of 2018 , 2017 , and 2016 , the Company determined that it was not more-likely that the fair value of the reporting units is less than their carrying amount. Accordingly, the Company did not perform the two-step goodwill impairment test on both the Company's Business and Consumer segments. The Company assessed qualitative facts while summarizing the totality of events and circumstances and considered the extent to which adverse events or circumstances could affect the reporting unit's fair value as well as the consideration of positive and mitigating events and circumstances that would affect the determination of whether it was more likely than not that the fair value of a reporting unit is less than its carrying amount.
Impairment of Long-Lived Assets	Impairment of Long-Lived Assets In accordance with ASC 360-10, “Accounting for the Impairment or Disposal of Long-lived Assets,” long-lived assets, such as property, plant and equipment and purchased intangibles subject to amortization are reviewed for impairment whenever events or changes in circumstances indicate that the carrying value of an asset may not be recoverable. The amount of any impairment is measured as the difference between the carrying value and the fair value of the impaired asset.
Revenue Recognition	Revenue Recognition The majority of the Company’s revenue is generated from monthly service revenues and related professional services from the sale of the LivePerson services. Revenues are recognized when control of these services is transferred to the Company's customers, in an amount that reflects the consideration the Company expects to be entitled to in exchange for those services. The Company determines revenue recognition through the following steps: • Identification of the contract, or contracts, with a customer; • Identification of the performance obligations in the contract; • Determination of the transaction price; • Allocation of the transaction price to the performance obligations in the contract; and • Recognition of revenue when, or as, the Company satisfies a performance obligation. Total revenue of $249.8 million recognized during the year ended December 31, 2018 , under Topic 606, was not materially different from what would have been recognized under Topic 605. The Company has made the following accounting policy election and elected to use a practical expedient specific to certain revenue streams, as permitted by the FASB, in applying Topic 606. The Company utilizes the right-to-invoice practical expedient with regard to the recognition of revenue upon the invoicing of certain revenue streams, as revenue for those streams are billed monthly Hosted Services- Business Revenue Hosted Services Business revenue is reported at the amount that reflects the ultimate consideration expected to be received and primarily consist of fees that provide customers access to LiveEngage, the Company’s enterprise-class, cloud-based platform. The Company has determined such access represents a stand-ready service provided continually throughout the contract term. As such, control and satisfaction of this stand-ready performance obligation is deemed to occur over time. The Company recognizes this revenue over time on a ratable basis over the contract term, beginning on the date that access to the LiveEngage platform is made available to the customer. The passage of time is deemed to be the most faithful depiction of the transfer of control of the services as the customer simultaneously receives and consumes the benefit provided by the Company’s performance. Subscription contracts are generally one year or longer in length, billed, monthly, quarterly or annually in advance. There is no significant variable consideration related to these arrangements. Additionally, for certain of the Company's larger customers, the Company may provide call center labor through an arrangement with one or more of several qualified vendors. For most of these customers, the Company passes the fee it incurs with the labor provider and its fee for the hosted services through to its customers in the form of a fixed fee for each order placed via the Company's online engagement solutions. For these Pay for Performance ("PFP") arrangements in accordance with ASC-606, "Principal Agent Considerations", the Company acts as a principal in a transaction if it controls the specified goods or services before they are transferred to the customer. Professional Services Revenues Professional services revenue primarily consists of fees for deployment and optimization services, as well as training delivered on an on-demand basis which is deemed to represent a distinct stand-ready performance obligation. Professional Services Revenues are reported at the amount that reflects the ultimate consideration the Company expects to receive in exchange for such services. Control for the majority of the Company's Professional Services contracts passes over time to the customer and is recognized ratably over the contracted period, as the passage of time is deemed to be the most faithful depiction of the transfer of control. For certain deployment services, which are not deemed to represent a distinct performance obligation, revenue will be recognized in the same manner as the fee for access to the LiveEngage platform, and as such will be recognized on a straight-line basis over the contract term. For services billed on a fixed price basis, revenue is recognized over time based on the proportion performed using inputs as the measure of progress toward complete satisfaction of the performance obligation. Professional service contracts are generally one year or longer in length, billed, monthly, quarterly or annually in advance. There is no significant variable consideration related to these arrangements. Contracts with Multiple Performance Obligations Some of the Company's contracts with customers contain multiple performance obligations. For these contracts, the Company accounts for individual performance obligations separately if they are distinct. The transaction price is allocated to the separate performance obligations on a relative standalone selling price basis. The Company determines the standalone selling prices based on its overall pricing objectives, taking into consideration market conditions and other factors, including the value of its contracts, the cloud applications sold, and the number and types of users within its contracts. Hosted Services- Consumer Revenue For revenue from the Company's Consumer segment generated from online transactions between Experts and Users, revenue is recognized at an amount net of Expert fees in accordance with ASC 606, “Principal Agent Considerations,” due primarily to the fact that the Expert is the primary obligor. Additionally, the Company performs as an agent without any risk of loss for collection, and is not involved in selecting the Expert or establishing the Expert’s fee. The Company collects a fee from the consumer and retains a portion of the fee, and then remits the balance to the Expert. Revenue from these transactions is recognized at the point in time when the transaction is complete and no significant performance obligations remain. Deferred Revenues The Company records deferred revenues when cash payments are received or due in advance of its performance. The increase in the deferred revenue balance for the year ended December 31, 2018 is primarily driven by cash payments received or due in advance of satisfying its performance obligations, partially offset by $32.7 million of revenues recognized that were included in the deferred revenue balance as of December 31, 2017 . The following table presents deferred revenue by revenue source (amounts in thousands): December 31, 2018 2017 Hosted services – Business $ 52,232 $ 27,011 Professional services – Business 2,783 8,552 Total deferred revenue - short term $ 55,015 $ 35,563 Hosted services – Business $ 19 $ — Professional services – Business 203 — Total deferred revenue - long term $ 222 $ — Disaggregated Revenue The following table presents the Company's revenues disaggregated by revenue source (amounts in thousands): December 31, 2018 2017 2016 Revenue: Hosted services – Business $ 197,474 $ 178,686 $ 183,551 Hosted services – Consumer 19,553 17,450 16,258 Professional services 32,811 22,740 22,970 Total revenue $ 249,838 $ 218,876 $ 222,779 Revenue by Geographic Location The Company is domiciled in the United States and has international operations in the United Kingdom, Asia-Pacific, Latin America and Western Europe, particularly France and Germany. The following table presents the Company's revenues attributable to domestic and foreign operations for the years ended (amounts in thousands): December 31, 2018 2017 2016 United States $ 146,702 $ 137,433 $ 146,733 Other Americas (1) 7,315 6,987 6,818 Total Americas 154,017 144,420 153,551 EMEA (2) (4) 71,318 56,310 50,511 APAC (3) 24,503 18,146 18,717 Total revenue $ 249,838 $ 218,876 $ 222,779 (1) Canada, Latin America and South America (2) Europe, the Middle East and Africa (“EMEA”) (3) Asia-Pacific (“APAC”) (4) Includes revenue from the United Kingdom of $46.5 million , $38.9 million , and $35.3 million for the year ended December 31, 2018 , 2017 , and 2016 , respectively. and from the Netherlands of $8.7 million , $2.0 million , and $2.1 million for the year ended December 31, 2018 , 2017 , and 2016 , respectively. Information about Contract Balances Amounts collected in advance of services being provided are accounted for as deferred revenue. Nearly all of the Company's deferred revenue balance is related to Hosted Services- Business Revenue. In some arrangements, the Company allows customers to pay for access to LiveEngage over the term of the software license. The Company refers to these as subscription transactions. Amounts recognized as revenue in excess of amounts billed are recorded as unbilled receivables. Unbilled receivables, anticipated to be invoiced in the next twelve months, are included in accounts receivable on the consolidated balance sheet. The opening and closing balances of the Company's accounts receivable, unbilled receivables, and deferred revenues are as follows (amounts in thousands): Accounts Receivable Unbilled Receivable Prepaid Commissions Deferred Revenue (current) Deferred Revenue (long term) Opening Balance as of December 31, 2017 $ 30,342 $ 7,584 $ 2,223 $ 35,563 $ — Increase (decrease), net 3,869 4,228 11,138 19,452 222 Ending Balance as of December 31, 2018 $ 34,211 $ 11,812 $ 13,361 $ 55,015 $ 222 As of December 31, 2018 , the Company expects to recognize the long term performance obligations in 2020.
Advertising Costs	Advertising Costs The Company expenses the cost of advertising and promoting its services as incurred in the sales and marketing expense on the consolidated statement of operations.
Stock-based Compensation	Stock-based Compensation In accordance with ASC Topic 718 -10, "Stock Compensation", the Company measures stock based awards at fair value and recognizes compensation expense for all share-based payment awards made to its employees and directors, including employee stock options. The Company estimates the fair value of stock options granted using the Black-Scholes valuation model. This model requires the Company to make estimates and assumptions including, among other things, estimates regarding the length of time an employee will retain vested stock options before exercising them, the estimated volatility of its common stock price and the number of options that will be forfeited prior to vesting. The fair value is then recognized on a straight line basis over the requisite service period of the award, which is generally three to four years. Changes in these estimates and assumptions can materially affect the determination of the fair value of the stock-based compensation and consequently, the related amount recognized in the consolidated statement of operations.
Deferred Rent	Deferred Rent The Company records rent expense on a straight-line basis over the term of the related lease. The difference between the rent expense recognized for financial reporting purposes and the actual payments made in accordance with the lease agreement is recognized as deferred rent liability included in other liabilities on the Company’s consolidated balance sheets.
Income Taxes	Income Taxes Income taxes are accounted for under the asset and liability method. Under this method, deferred tax assets and liabilities are recognized for the future tax consequences attributable to differences between the financial statement carrying amounts of existing assets and liabilities and their respective tax bases and operating loss and tax credit carryforwards. Deferred tax assets and liabilities are measured using enacted tax rates expected to apply to taxable income in the years in which those temporary differences are expected to be recovered or settled. The effect on deferred tax assets and liabilities of a change in tax rates is recognized in results of operations in the period that the tax change occurs. In evaluating our ability to recover our deferred tax assets in the jurisdiction from which they arise, we consider all available positive and negative evidence, including scheduled reversals of deferred tax liabilities, projected future taxable income, tax-planning strategies, and results of recent operations. We include interest accrued on the underpayment of income taxes in interest expense and penalties, if any, related to unrecognized tax benefits in general and administrative expenses. Valuation allowances are established, when necessary, to reduce deferred tax assets to the amount expected to be realized
Comprehensive Loss	Comprehensive Loss In accordance with ASC 220, "Comprehensive Income", the Company reports by major components and as a single total, the change in its net assets during the period from non-owner sources. Comprehensive income (loss) consists of net income (loss), and accumulated other comprehensive income (loss), which includes certain changes in equity that are excluded from net income (loss). The Company’s comprehensive loss for all periods presented is related to the effect of foreign currency translation.
Recently Issued Accounting Standards	Recently Issued Accounting Standards In August 2018, the Financial Accounting Standards Board (“FASB”) issued Accounting Standards Update ("ASU") No. 2018-15 "Customer’s Accounting for Implementation Costs Incurred in a Cloud Computing Arrangement That Is a Service Contract; Disclosures for Implementation Costs Incurred for Internal-Use Software and Cloud Computing Arrangements" (“ASU 2018-15”). This standard aligns the accounting for implementation costs incurred in a hosting arrangement that is a service contract with the accounting for implementation costs incurred to develop or obtain internal-use software under Accounting Standards Codification ("ASC") 350-40, in order to determine which costs to capitalize and recognize as an asset. ASU 2018-15 is effective for annual reporting periods, and interim periods within those years, beginning after December 15, 2019, and can be applied either prospectively to implementation costs incurred after the date of adoption or retrospectively to all arrangements. The Company is currently in the process of evaluating the impact of the adoption of ASU 2018-230 on its consolidated financial statements. In June 2018, the FASB issued ASU No. 2018-07 "Compensation —Stock Compensation (Topic 718) —Improvements to Nonemployee Share-Based Payment Accounting" ("ASU 2018-07"). This new standard expands the scope of Topic 718, Compensation—Stock Compensation (which currently only includes share-based payments to employees) to include share-based payments issued to non-employees for goods or services. Consequently, the accounting for share-based payments to non-employees and employees will be substantially aligned. ASU 2018-07 is effective for public companies for fiscal years beginning after December 15, 2018, including interim periods within that fiscal year. The Company is currently evaluating the impact of this updated standard, but does not believe this update will have a significant impact on its consolidated financial statements. In March 2018, the FASB issued ASU No. 2018-05 "Income Taxes (Topic 740): Amendments to SEC Paragraphs Pursuant to SEC Staff Accounting Bulletin No. 118" ("ASU 2018-05"). This new standard adds SEC paragraphs pursuant to the SEC Staff Accounting Bulletin No. 118, which expresses the view of the staff regarding application of Topic 740, Income Taxes, in the reporting period that includes December 22, 2017, the date on which the Tax Cuts and Jobs Act was signed into law. ASU 2018-05 is effective upon inclusion in the FASB Codification. The Company evaluated the impact of this updated standard and determined that the tax on unremitted earnings is zero due to the overall accumulated deficit in earnings and profits. In February 2018, the FASB issued ASU No. 2018-02 "Income Statement—Reporting Comprehensive Income (Topic 220): Reclassification of Certain Tax Effects from Accumulated Other Comprehensive Income" ("ASU 2018-02"). This new standard allows a reclassification from accumulated other comprehensive income to retained earnings for stranded tax effects resulting from the Tax Cuts and Jobs Act. The amendments in ASU 2018-02 affects any entity that is required to apply the provisions of Topic 220 and has items of other comprehensive income for which the related tax effects are presented in other comprehensive income as required by GAAP. ASU 2018-02 is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2018, for public companies. Early adoption is permitted in any interim period or fiscal years before the effective date of the standard. The Company does not expect the adoption of ASU 2018-02 to have a material effect on its financial position, results of operations or cash flows. In August 2017, the FASB issued ASU No. 2017-12 "Derivatives and Hedging (Topic 815): Targeted Improvements to Accounting for Hedging Activities" ("ASU 2017-12"). This new standard refines and expands hedge accounting for both financial (e.g., interest rate) and commodity risks. Its provisions create more transparency around how economic results are presented, both on the face of the financial statements and in the footnotes, for investors and analysts. ASU 2017-12 is effective for fiscal years, and interim periods within those fiscal years, beginning after December 15, 2018, for public companies. Early adoption is permitted in any interim period or fiscal years before the effective date of the standard. The Company does not expect the adoption of ASU 2017-12 to have a material effect on its financial position, results of operations or cash flows. In January 2017, FASB issued ASU No. 2017-04, "Intangibles —Goodwill and Other (Topic 350): Simplifying the Test for Goodwill Impairment" (“ASU 2017-04”). This update addresses concerns over the cost and complexity of the two-step goodwill impairment test. The amendments in this update remove the second step of the test. An entity will apply a one-step quantitative test and record the amount of goodwill impairment as the excess of a reporting unit's carrying amount over its fair value, not to exceed the total amount of goodwill allocated to the reporting unit. The new guidance does not amend the optional qualitative assessment of goodwill impairment. ASU 2017-04 is effective for financial statements issued for annual periods beginning after December 15, 2019, and interim periods within those annual periods. The Company does not expect the adoption of ASU 2017-04 to have a material effect on its financial position, results of operations or cash flows. In February 2016, the FASB issued ASU No. 2016-02, “Leases” (“ASU 2016-02”). ASU 2016-02 requires lessees to recognize the following for all leases (with the exception of short-term leases) at the commencement date: a lease liability, which is a lessee‘s obligation to make lease payments arising from a lease, measured on a discounted basis; and a right-of-use asset, which is an asset that represents the lessee’s right to use, or control the use of, a specified asset for the lease term. Under the new guidance, lessor accounting is largely unchanged. The new lease guidance also simplified the accounting for sale and leaseback transactions primarily because lessees must recognize lease assets and lease liabilities. Lessees will no longer be provided with a source of off-balance sheet financing. Lessees (for capital and operating leases) and lessors (for sales-type, direct financing, and operating leases) may apply a modified retrospective transition approach for leases existing at, or entered into after, the beginning of the earliest comparative period presented in the financial statements. The modified retrospective approach would not require any transition accounting for leases that expired before the earliest comparative period presented. Lessees and lessors may not apply a full retrospective transition approach. The Company plans on adopting the standard using the modified transition approach or the transition option available where the Company would recognize a cumulative-effect adjustment to the opening balance of retained earnings in the period of adoption. ASU 2016-02 is effective for financial statements issued for annual periods beginning after December 15, 2018. The Company continues to implement changes to its systems, processes and controls, in conjunction with its review of existing lease agreements. The Company expects its leases designated as operating leases in Note 9, “Contractual Obligations,” will be reported on the consolidated balance sheets upon adoption, which will materially increase its total assets and liabilities. The adoption of this ASU will result in the recognition of operating lease assets and liabilities of approximately $10.0 million. The Company does not expect the adoption of ASU 2016-02 to have a material impact to its consolidated statements of operations or to have any impact on its total cash flows from operating, investing or financing activities. Recently Adopted Accounting Pronouncements In May 2014, the FASB issued ASU No. 2014-09, "Revenue from Contracts with Customers" ("Topic 606"). Topic 606 supersedes the revenue recognition requirements in ASC Topic 605, "Revenue Recognition" ("Topic 605"), and requires the recognition of revenue when promised goods or services are transferred to customers in an amount that reflects the considerations to which the entity expects to be entitled to in exchange for those goods or services. Topic 606 also includes Subtopic 340-40, "Other Assets and Deferred Costs - Contracts with Customers", which requires the deferral of incremental costs of obtaining a contract with a customer. Collectively, the Company refers to Topic 606 and Subtopic 340-40 as the "new standard." The Company adopted the requirements of the new standard as of January 1, 2018, utilizing the modified retrospective method applied to those contracts which were not completed as of January 1, 2018. Results for the reporting periods beginning after January 1, 2018 are presented under the new standard, while prior period amounts are not adjusted and continue to be reported in accordance with its historic accounting under Topic 605. The impact of adopting the new standard as of January 1, 2018 on revenues was not material. The primary impact of adopting the new standard relates to the deferral of incremental commission costs of obtaining subscription contracts. The Company recorded an addition to opening retained earnings of $0.7 million as of January 1, 2018 due to the impact of adopting the new standard, with the impact related to the deferral of incremental commission costs. Under Topic 605, the Company deferred only direct and incremental commission costs to obtain a contract and amortized those costs on a straight-line basis over the term of the related subscription contract, which was generally one year. Under the new standard, the Company defers all incremental commission costs to obtain the contract. The prepaid commission balance as of December 31, 2018 is $13.4 million . The Company amortizes these costs over the related period of benefit using the customer expected life that the Company determined to be three to five years which is consistent with the transfer to the customer of the services to which the asset relates.

Description of Business and S_3

Description of Business and Summary of Significant Accounting Policies (Tables)	12 Months Ended
	Dec. 31, 2018
Accounting Policies [Abstract]
Schedule of Activity in the Allowance for Doubtful Accounts	The activity in the allowance for doubtful accounts is as follows (amounts in thousands): Year Ended December 31, Beginning Balance Additions Charged to Costs and Expenses Deductions / Write-Offs Ending Balance 2016 $ 1,184 $ 1,831 $ (1,283 ) $ 1,732 2017 $ 1,732 $ 1,895 $ (2,309 ) $ 1,318 2018 $ 1,318 $ 1,814 $ (856 ) $ 2,276

Net Loss per Share (Tables)

Net Loss per Share (Tables)	12 Months Ended
	Dec. 31, 2018
Earnings Per Share [Abstract]
Reconciliation of Shares Used in Calculating Basic and Diluted Earnings Per Share	A reconciliation of shares used in calculating basic and diluted earnings per share follows: Year Ended December 31, 2018 2017 2016 Basic 59,203,400 56,358,017 56,063,777 Effect of assumed exercised options — — — Diluted 59,203,400 56,358,017 56,063,777

Segment Information (Tables)

Segment Information (Tables)	12 Months Ended
	Dec. 31, 2018
Segment Reporting [Abstract]
Summary Of Financial Information By Segment	Summarized financial information by segment for the year ended December 31, 2018 , based on the Company’s internal financial reporting system utilized by the Company’s chief operating decision maker, follows (amounts in thousands): Business Consumer Corporate Consolidated Revenue: Hosted services – Business $ 197,474 $ — $ — $ 197,474 Hosted services – Consumer — 19,553 — 19,553 Professional services 32,811 — — 32,811 Total revenue 230,285 19,553 — 249,838 Cost of revenue 58,420 4,059 — 62,479 Sales and marketing 94,339 9,005 — 103,344 Amortization of purchased intangibles 1,670 — — 1,670 Unallocated corporate expenses — — 106,048 106,048 Operating income (loss) $ 75,856 $ 6,489 $ (106,048 ) $ (23,703 ) Summarized financial information by segment for the year ended December 31, 2017 , based on the Company’s internal financial reporting system utilized by the Company’s chief operating decision maker, follows (amounts in thousands): Business Consumer Corporate Consolidated Revenue: Hosted services – Business $ 178,686 $ — $ — $ 178,686 Hosted services – Consumer — 17,450 — 17,450 Professional services 22,740 — — 22,740 Total revenue 201,426 17,450 — 218,876 Cost of revenue 54,600 3,605 — 58,205 Sales and marketing 82,420 8,485 — 90,905 Amortization of purchased intangibles 1,840 — — 1,840 Unallocated corporate expenses — — 85,752 85,752 Operating income (loss) $ 62,566 $ 5,360 $ (85,752 ) $ (17,826 ) Summarized financial information by segment for the year ended December 31, 2016 , based on the Company’s internal financial reporting system utilized by the Company’s chief operating decision maker, follows (amounts in thousands): Business Consumer Corporate Consolidated Revenue: Hosted services – Business $ 183,551 $ — $ — $ 183,551 Hosted services – Consumer — 16,258 — 16,258 Professional services 22,970 — — 22,970 Total revenue 206,521 16,258 — 222,779 Cost of revenue 60,352 2,809 — 63,161 Sales and marketing 82,063 7,466 — 89,529 Amortization of purchased intangibles 3,885 — — 3,885 Unallocated corporate expenses — — 85,613 85,613 Operating income (loss) $ 60,221 $ 5,983 $ (85,613 ) $ (19,409 )
Long-Lived Assets By Geographic Region	The following table presents the Company's long-lived assets by geographic region for the periods presented (amounts in thousands): December 31, 2018 2017 United States $ 122,019 $ 93,845 Israel 13,598 13,940 Australia 8,970 9,496 Netherlands 7,426 7,495 Other (1) 3,130 2,711 Total long-lived assets $ 155,143 $ 127,487 (1) United Kingdom, Germany, Japan, France, and Italy

Property and Equipment (Tables)

Property and Equipment (Tables)	12 Months Ended
	Dec. 31, 2018
Property, Plant and Equipment [Abstract]
Schedule of Property And Equipment	The following table presents the detail of property and equipment for the periods presented (amounts in thousands): December 31, 2018 2017 Computer equipment and software $ 79,161 $ 92,079 Furniture, equipment and building improvements 14,132 15,355 Internal-use software development costs 19,240 8,736 112,533 116,170 Less: accumulated depreciation (68,798 ) (81,465 ) Total $ 43,735 $ 34,705

Goodwill and Intangible Assets

Goodwill and Intangible Assets (Tables)	12 Months Ended
	Dec. 31, 2018
Goodwill and Intangible Assets Disclosure [Abstract]
Schedule of Changes in Goodwill	The changes in the carrying amount of goodwill for the year ended December 31, 2018 are as follows (amounts in thousands): Business Consumer Total Balance as of December 31, 2017 $ 72,507 $ 8,024 $ 80,531 Adjustments to goodwill: Acquisitions 14,606 — 14,606 Foreign exchange adjustments (106 ) — (106 ) Balance as of December 31, 2018 $ 87,007 $ 8,024 $ 95,031 The changes in the carrying amount of goodwill for the year ended December 31, 2017 are as follows (amounts in thousands): Business Consumer Total Balance as of December 31, 2016 $ 72,221 $ 8,024 $ 80,245 Adjustments to goodwill: Foreign exchange adjustments 286 — 286 Balance as of December 31, 2017 $ 72,507 $ 8,024 $ 80,531
Summary of Intangible Assets	Intangible assets are summarized as follows (see Note 8) (amounts in thousands): December 31, 2018 Gross Carrying Amount Accumulated Amortization Net Carrying Amount Weighted Average Amortization Period Amortizing intangible assets: Technology $ 30,447 $ (23,615 ) $ 6,832 5.3 years Customer relationships 17,219 (11,786 ) 5,433 8.4 years Trade names 1,286 (1,286 ) — 2.1 years Non-compete agreements 1,436 (1,436 ) — 2.3 years Patents 2,074 (534 ) 1,540 12.4 years Other 262 (235 ) 27 2.7 years Total $ 52,724 $ (38,892 ) $ 13,832 December 31, 2017 Gross Carrying Amount Accumulated Amortization Net Carrying Amount Weighted Average Amortization Period Amortizing intangible assets: Technology $ 27,882 $ (22,197 ) $ 5,685 5.3 years Customer relationships 15,978 (10,457 ) 5,521 8.0 years Trade names 1,289 (1,283 ) 6 2.1 years Non-compete agreements 1,439 (1,439 ) — 2.3 years Patents 1,620 (493 ) 1,127 13.1 years Other 262 (235 ) 27 2.7 years Total $ 48,470 $ (36,104 ) $ 12,366
Schedule of Future Amortization Expense	Estimated amortization expense for the next five years are as follows (amounts in thousands): Estimated Amortization Expense 2019 $ 2,901 2020 2,708 2021 2,498 2022 2,143 2023 902 Thereafter 2,680 Total $ 13,832

Accrued Liabilities and Other_2

Accrued Liabilities and Other Current Liabilities (Tables)	12 Months Ended
	Dec. 31, 2018
Payables and Accruals [Abstract]
Schedule of Accrued Liabilities	The following table presents the detail of accrued liabilities and other current liabilities for the periods presented (amounts in thousands): December 31, 2018 2017 Payroll and other employee related costs $ 19,014 $ 16,431 Professional services, consulting and other vendor fees 17,461 15,674 Unrecognized tax benefits 1,913 4,924 Sales commissions 6,239 5,259 Contingent earn-out (Note 8) 2,372 — Restructuring 977 2,338 Other 2,686 3,385 Total $ 50,662 $ 48,011

Fair Value Measurements (Tables

Fair Value Measurements (Tables)	12 Months Ended
	Dec. 31, 2018
Fair Value Disclosures [Abstract]
Schedule of Assets and Liabilities Measured at Fair Value on Recurring Basis	The Company's assets and liabilities that are measured at fair value on a recurring basis, by level, within the fair value hierarchy as of December 31, 2018 and December 31, 2017 , are summarized as follows (amounts in thousands). The Company did not have any restricted cash balance as of December 31, 2018 . The Company's restricted cash balance of $1.5 million at December 31, 2017 is not held in a money market account and is not included in the following table. December 31, 2018 December 31, 2017 Level 1 Level 2 Level 3 Total Level 1 Level 2 Level 3 Total Assets: Cash equivalents: Money market funds $ 2,828 $ — $ — $ 2,828 $ 2,806 $ — $ — $ 2,806 Foreign currency derivative contracts — — — — — 65 — 65 Total assets $ 2,828 $ — $ — $ 2,828 $ 2,806 $ 65 $ — $ 2,871 Liabilities: Contingent earn-out $ — $ — $ 2,372 $ 2,372 $ — $ — $ — $ — Foreign currency derivative contracts — — — — — 2 — 2 Total liabilities $ — $ — $ 2,372 $ 2,372 $ — $ 2 $ — $ 2
Schedule of Changes in Fair Value of Level 3 Liabilities	The changes in fair value of the Level 3 liabilities are as follows (amounts in thousands): Contingent Earn-Out December 31, 2018 2017 Balance, Beginning of year $ — $ 210 Conversable, Inc. addition (see Note 7) 1,496 — AdvantageTec, Inc. addition (see Note 7) 876 — Cash payment — (210 ) Balance, End of year $ 2,372 $ —
Schedule of Derivative Instruments	The following summarizes certain information regarding the Company’s outstanding foreign currency derivative contracts related primarily to intercompany receivables and payables for the periods presented (in thousands): December 31, 2018 December 31, 2017 Notional amount of foreign currency derivative contracts $ — $ 2,866 Fair value of foreign currency derivatives contracts — 63
Schedule of Derivative Assets at Fair Value	The fair value of the Company’s derivative instruments is summarized below (in thousands): Fair Value of Derivative Instruments Balance Sheet Location December 31, 2018 December 31, 2017 Derivative Assets Derivatives not designated as hedging instruments: Foreign currency derivatives contracts Prepaid expenses and other current assets $ — $ 65 Derivative Liabilities Derivatives not designated as hedging instruments: Foreign currency derivatives Accrued expenses and other liabilities $ — $ 2
Schedule of Derivative Liabilities at Fair Value	The fair value of the Company’s derivative instruments is summarized below (in thousands): Fair Value of Derivative Instruments Balance Sheet Location December 31, 2018 December 31, 2017 Derivative Assets Derivatives not designated as hedging instruments: Foreign currency derivatives contracts Prepaid expenses and other current assets $ — $ 65 Derivative Liabilities Derivatives not designated as hedging instruments: Foreign currency derivatives Accrued expenses and other liabilities $ — $ 2
Schedule of Gains (Losses) on Derivative Instruments Recognized in the Income Statement	The following summarizes certain information regarding the Company’s derivatives that are not designated or are not effective as hedges (in thousands): Gain (losses) on Derivative Instruments Recognized in Income Statement Income Statement Location December 31, 2018 December 31, 2017 Foreign currency derivatives contracts Other (Expense) Income, net $ (50 ) $ 236

Commitments and Contingencies (

Commitments and Contingencies (Tables)	12 Months Ended
	Dec. 31, 2018
Commitments and Contingencies Disclosure [Abstract]
Future Minimum Lease Payments Under Non-Cancelable Operating Leases	uture minimum lease payments under non-cancellable operating leases (with an initial or remaining lease terms in excess of one year) are as follows (amounts in thousands): Year Ending December 31, Operating Leases 2019 $ 8,488 2020 6,139 2021 5,477 2022 2,649 2023 883 Thereafter 61 Total minimum lease payments $ 23,697 Our other noncurrent liabilities in the consolidated balance sheet include unrecognized tax benefits. As of December 31, 2018, we had gross unrecognized tax benefits of $1.9 million. At this time, we are unable to make a reasonably reliable estimate of the timing of payments in individual years in connection with these tax liabilities; therefore, such amounts are not included in the above contractual obligation table.

Stockholders' Equity (Tables)

Stockholders' Equity (Tables)	12 Months Ended
	Dec. 31, 2018
Equity [Abstract]
Weighted Average Assumptions of Fair Value Options Using Black-Scholes Option-Pricing Model	The fair value of each option grant is estimated on the date of grant using the Black-Scholes option-pricing model with the following weighted average assumptions for the years ended December 31, 2018 , 2017 and 2016 : December 31, 2018 2017 2016 Dividend yield —% —% —% Risk-free interest rate 2.5% – 3.1% 1.7% – 2.1% 1.0% – 1.8% Expected life (in years) 5.0 5.0 5.0 Historical volatility 43.5% – 48.4% 46.6% – 48.1% 46.8% – 48.2%
Schedule of Stock Option Activity and Weighted Average Exercise Prices	A summary of the Company’s stock option activity and weighted average exercise prices follows: Stock Option Activity Weighted Average Remaining Contractual Term (in years) Aggregate Intrinsic Value (in thousands) Options (in thousands) Weighted Balance outstanding at December 31, 2015 9,144 $ 11.05 Granted 635 7.32 Exercised (325 ) 5.66 Cancelled or expired (1,685 ) 11.49 Balance outstanding at December 31, 2016 7,769 $ 10.88 6.05 $ 2,641 Options vested and expected to vest 7,348 $ 11.00 5.90 $ 2,529 Options exercisable at December 31, 2016 5,580 $ 11.31 5.27 $ 2,347 Balance outstanding at December 31, 2016 7,769 $ 10.88 Granted 2,042 9.87 Exercised (854 ) 8.80 Cancelled or expired (998 ) 11.98 Balance outstanding at December 31, 2017 7,959 $ 10.71 5.85 $ 14,881 Options vested and expected to vest 7,163 $ 10.75 5.49 $ 13,197 Options exercisable at December 31, 2017 5,163 $ 11.17 4.50 $ 8,648 Balance outstanding at December 31, 2017 7,959 $ 10.71 Granted 2,033 15.00 Exercised (3,120 ) 10.70 Cancelled or expired (606 ) 10.03 Balance outstanding at December 31, 2018 6,266 $ 12.13 6.55 $ 43,348 Options vested and expected to vest 5,550 $ 11.89 6.28 $ 39,521 Options exercisable at December 31, 2018 3,278 $ 11.12 4.64 $ 25,367
Schedule of Share-based Compensation, Shares Authorized under Stock Option Plans, by Exercise Price Range	The following table summarizes information about outstanding and vested stock options as of December 31, 2018 : Options Outstanding Options Exercisable Range of Exercise Prices Number of Shares Outstanding (in thousands) Weighted-Average Remaining Contractual Life (Years) Weighted-Average Exercise Price Number of Shares (in thousands) Weighted-Average Exercise Price $1.79 - $7.60 1,081 6.37 $ 7.03 570 $ 6.70 $7.95 - $9.55 635 5.90 9.20 488 9.18 $9.90 - $10.13 640 5.33 10.09 636 10.09 $10.31 - $11.96 660 6.77 11.26 388 11.00 $12.09 - $12.32 39 2.31 12.29 39 12.29 $12.45 - $12.45 930 9.13 12.45 — — $12.46 - $13.59 684 3.42 13.31 684 13.31 $14.30 - $15.96 678 7.22 14.73 146 14.97 $16.05 - $21.75 770 6.85 18.30 327 17.45 $22.04 - $23.50 149 9.56 22.91 — — 6,266 6.55 $ 12.13 3,278 $ 11.12
Schedule of Share-based Compensation, Restricted Stock Units Award Activity	Restricted Stock Unit Activity A summary of the Company’s restricted stock units (“RSUs”) activity and weighted average exercise prices follows: Restricted Stock Unit Activity Number of Shares (in thousands) Weighted Average Grant Date Fair Value (Per Share) Aggregate Fair Value (in thousands) Balance outstanding at December 31, 2015 1,202 $ 10.31 $ 6,220 Awarded 571 6.32 — Released (394 ) 10.31 — Forfeited (191 ) 10.01 — Non-vested and outstanding at December 31, 2016 1,188 $ 8.44 $ 8,968 Balance outstanding at December 31, 2016 1,188 $ 8.44 $ 8,968 Awarded 332 8.16 — Released (363 ) 8.48 — Forfeited (284 ) 8.46 — Non-vested and outstanding at December 31, 2017 873 $ 8.29 $ 10,053 Balance outstanding at December 31, 2017 873 $ 8.29 $ 10,053 Awarded 2,568 17.02 — Released (361 ) 9.49 — Forfeited (390 ) 9.49 — Non-vested and outstanding at December 31, 2018 2,690 $ 15.81 $ 50,756 Expected to vest 1,875 $ 14.83 $ 35,357

Income Taxes (Tables)

Income Taxes (Tables)	12 Months Ended
	Dec. 31, 2018
Income Tax Disclosure [Abstract]
Schedule of Domestic and Foreign Components of Income Before Provision for Income Taxes	The domestic and foreign components of (loss) before provision for income taxes consist of the following (amounts in thousands): Year Ended December 31, 2018 2017 2016 United States $ (38,078 ) $ (25,585 ) $ (40,774 ) Israel 3,163 3,458 15,622 United Kingdom 3,690 2,087 2,345 Netherlands 3,235 1,568 3,104 Australia 686 (1,979 ) (2,774 ) Germany 2,900 2,424 2,085 Other (1) 230 337 453 $ (24,174 ) $ (17,690 ) $ (19,939 ) (1) Includes Japan, Italy, Singapore, Canada, and France
Schedule of Provision For Income Taxes	The provision for income taxes consists of the following (amounts in thousands): Year Ended December 31, 2018 2017 2016 Current income taxes: U.S. Federal $ (1,932 ) $ — $ 1,829 State and local 67 47 27 Foreign 3,032 2,852 2,226 Total current income taxes 1,167 2,899 4,082 Deferred income taxes: U.S. Federal (295 ) (1,289 ) 841 State and local (28 ) (1,144 ) 99 Foreign 14 35 912 Total deferred income taxes (309 ) (2,398 ) 1,852 Total provision for income taxes $ 858 $ 501 $ 5,934
Schedule of Reconciliation of Federal Statutory Tax Rate to Effective Income Tax Rate	The difference between the total income taxes computed at the federal statutory rate and the provision for income taxes consists of the following: Year Ended December 31, 2018 2017 2016 Federal statutory rate 21.00 % 34.00 % 34.00 % State taxes, net of federal benefit 3.30 % 4.09 % 3.24 % Non-deductible expenses – ISO 4.73 % (0.78 )% (1.85 )% Global intangible low tax income inclusion (7.99 )% — % — % Non-deductible expenses – Other (2.58 )% (1.19 )% (0.88 )% Foreign tax rate differential (1.34 )% (1.97 )% 0.89 % Change in valuation allowance (28.91 )% 26.12 % (53.55 )% Stock based compensation 6.10 % — % — % Return to provision true-up adjustment — % — % (9.22 )% Effect of new tax legislation — % (56.84 )% — % Other 2.09 % (6.26 )% (2.42 )% Total provision for income taxes (3.60 )% (2.83 )% (29.79 )%
Schedule of Federal Deferred Tax Assets and Deferred Tax Liabilities	The effects of temporary differences and federal NOL carryforwards that give rise to significant portions of federal deferred tax assets and deferred tax liabilities at December 31, 2018 and 2017 are presented below (amounts in thousands): Year Ended December 31, 2018 2017 Deferred tax assets: Net operating loss carryforwards $ 18,083 $ 8,093 Accounts payable and accrued expenses 4,024 4,429 Non-cash compensation 9,597 9,510 Intangibles amortization 5,691 5,513 Allowance for doubtful accounts 315 232 Total deferred tax assets 37,710 27,777 Less valuation allowance (30,185 ) (23,260 ) Deferred tax assets, net of valuation allowance 7,525 4,517 Deferred tax liabilities: Property and equipment (3,736 ) (2,010 ) Goodwill amortization and contingent earn-out adjustments (4,172 ) (2,669 ) Total deferred tax liabilities (7,908 ) (4,679 ) Net deferred tax liabilities $ (383 ) $ (162 )
Schedule of Unrecognized Tax Benefits Roll Forward	A reconciliation of the beginning and ending amount of unrecognized tax benefits is as follows (in thousands): Year Ended December 31, 2018 2017 Unrecognized tax benefits balance at January 1 $ 4,924 $ 4,240 Gross increase for tax positions of prior years — — Gross increase for tax positions of current years 405 684 Decrease due to expiration of statue (445 ) — Decrease due to settlement (2,963 ) — Gross unrecognized tax benefits at December 31 $ 1,921 $ 4,924

Restructuring Costs (Tables)

Restructuring Costs (Tables)	12 Months Ended
	Dec. 31, 2018
Restructuring and Related Activities [Abstract]
Schedule of Restructuring and Related Costs	The following table presents the detail of the liability for the Company’s restructuring charges for the periods presented (amounts in thousands): December 31, 2018 December 31, 2017 Balance, Beginning of the year $ 2,338 $ 2,551 Severance and other associated costs 4,468 648 Cash payments (5,829 ) (2,807 ) Wind down costs of legacy platform — 1,946 Balance, End of year $ 977 $ 2,338 The following table presents the detail of expenses for the Company’s restructuring charges for the periods presented (amounts in thousands): December 31, 2018 December 31, 2017 December 31, 2016 Contract termination benefit $ — $ — $ (384 ) Severance and other associated costs 4,468 648 1,585 Wind down costs of legacy platform — 1,946 1,168 Total restructuring costs $ 4,468 $ 2,594 $ 2,369

Description of Business and S_4

Description of Business and Summary of Significant Accounting Policies - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Jan. 01, 2018
Organization Consolidation And Summary Of Significant Accounting Policies [Line Items]
Accounts receivable	$ 46,023	$ 37,926
Allowance for Doubtful Accounts Receivable [Roll Forward]
Beginning Balance	1,318	1,732	$ 1,184
Additions Charged to Costs and Expenses	1,814	1,895	1,831
Deductions / Write-Offs	(856)	(2,309)	(1,283)
Ending Balance	2,276	1,318	1,732
Depreciation	14,188	12,358	12,011
Capitalized computer software	11,700	8,300	3,700
Revenue	249,838	218,876	222,779
Advertising costs	17,400	$ 15,800	$ 10,900
Prepaid commissions	$ 13,400
ASU No. 2014-09
Allowance for Doubtful Accounts Receivable [Roll Forward]
Cumulative effect on retained earnings upon adoption of new accounting standard				$ 700
Software and software development costs
Allowance for Doubtful Accounts Receivable [Roll Forward]
Property and equipment, useful life	3 years
Minimum
Allowance for Doubtful Accounts Receivable [Roll Forward]
Requisite service period	3 years
Minimum | Computer equipment and software
Allowance for Doubtful Accounts Receivable [Roll Forward]
Property and equipment, useful life	3 years
Maximum
Allowance for Doubtful Accounts Receivable [Roll Forward]
Requisite service period	4 years
Maximum | Computer equipment and software
Allowance for Doubtful Accounts Receivable [Roll Forward]
Property and equipment, useful life	5 years
Major customer
Organization Consolidation And Summary Of Significant Accounting Policies [Line Items]
Accounts receivable	$ 10,000

Description of Business and S_5

Description of Business and Summary of Significant Accounting Policies - Deferred Revenue (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Sep. 30, 2018	Dec. 31, 2017
Disaggregation of Revenue [Line Items]
Total deferred revenue - short term	$ 55,015	$ 55,015	$ 35,563
Total deferred revenue - long term	222	$ 222	0
Hosted Services - Business
Disaggregation of Revenue [Line Items]
Total deferred revenue - short term	52,232		27,011
Total deferred revenue - long term	19		0
Professional Services
Disaggregation of Revenue [Line Items]
Total deferred revenue - short term	2,783		8,552
Total deferred revenue - long term	$ 203		$ 0

Description of Business and S_6

Description of Business and Summary of Significant Accounting Policies - Disaggregation of Revenue (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Disaggregation of Revenue [Line Items]
Revenue	$ 249,838	$ 218,876	$ 222,779
Hosted Services - Business
Disaggregation of Revenue [Line Items]
Revenue	197,474	178,686	183,551
Hosted Services - Consumer
Disaggregation of Revenue [Line Items]
Revenue	19,553	17,450	16,258
Professional Services
Disaggregation of Revenue [Line Items]
Revenue	$ 32,811	$ 22,740	$ 22,970

Description of Business and S_7

Description of Business and Summary of Significant Accounting Policies - Revenue by Geographic Region (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Disaggregation of Revenue [Line Items]
Revenue	$ 249,838	$ 218,876	$ 222,779
United States
Disaggregation of Revenue [Line Items]
Revenue	146,702	137,433	146,733
Other Americas
Disaggregation of Revenue [Line Items]
Revenue	7,315	6,987	6,818
Total Americas
Disaggregation of Revenue [Line Items]
Revenue	154,017	144,420	153,551
EMEA
Disaggregation of Revenue [Line Items]
Revenue	71,318	56,310	50,511
APAC
Disaggregation of Revenue [Line Items]
Revenue	24,503	18,146	18,717
United Kingdom
Disaggregation of Revenue [Line Items]
Revenue	46,500	38,900	35,300
Netherlands
Disaggregation of Revenue [Line Items]
Revenue	$ 8,700	$ 2,000	$ 2,100

Description of Business and S_8

Description of Business and Summary of Significant Accounting Policies Description of Business and Summary of Significant Accounting Policies - Receivables and Deferred Revenue (Details) $ in Thousands	9 Months Ended
	Sep. 30, 2018USD ($)
Contract Balances [Roll Forward]
Opening balance, Receivable	$ 37,926
Opening balance, Deferred Revenue (current)	35,563
Increase (decrease) in current deferred revenue (current)	19,452
Closing balance, Deferred Revenue (current)	55,015
Ending balance, Deferred revenue (long-term)	0
Increase (decrease) in long-term deferred revenue, net	222
Closing balance, Deferred revenue (long-term)	222
Accounts Receivable
Contract Balances [Roll Forward]
Opening balance, Receivable	30,342
Increase (decrease) in accounts receivable, net	3,869
Closing balance, Receivable	34,211
Unbilled Receivable
Contract Balances [Roll Forward]
Opening balance, Receivable	7,584
Increase (decrease) in unbilled receivable, net	4,228
Closing balance, Receivable	11,812
Opening balance, Prepaid Commissions	2,223
Increase (decrease) in prepaid commissions	11,138
Closing balance, Prepaid Commissions	$ 13,361

Net Loss per Share (Details)

Net Loss per Share (Details) - shares	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Earnings Per Share [Abstract]
Shares excluded from computation of earnings per share (in shares)	8,957,672	8,831,798	8,956,932
Weighted Average Number of Shares Outstanding
Basic (in shares)	59,203,400	56,358,017	56,063,777
Effect of assumed exercised options (in shares)	0	0	0
Diluted (in shares)	59,203,400	56,358,017	56,063,777

Segment Information - Narrative

Segment Information - Narrative (Details)	12 Months Ended
	Dec. 31, 2018segment
Segment Reporting [Abstract]
Number of operating segments	2

Segment Information - Summary o

Segment Information - Summary of Financial Information By Segment (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Segment Reporting Information [Line Items]
Total revenue	$ 249,838	$ 218,876	$ 222,779
Cost of revenue	62,479	58,205	63,161
Sales and marketing	103,344	90,905	89,529
Amortization of purchased intangibles	1,670	1,840	3,885
Unallocated corporate expenses	106,048	85,752	85,613
Loss from operations	(23,703)	(17,826)	(19,409)
Corporate
Segment Reporting Information [Line Items]
Unallocated corporate expenses	106,048	85,752	85,613
Loss from operations	(106,048)	(85,752)	(85,613)
Business | Operating Segments
Segment Reporting Information [Line Items]
Total revenue	230,285	201,426	206,521
Cost of revenue	58,420	54,600	60,352
Sales and marketing	94,339	82,420	82,063
Amortization of purchased intangibles	1,670	1,840	3,885
Loss from operations	75,856	62,566	60,221
Consumer | Operating Segments
Segment Reporting Information [Line Items]
Total revenue	19,553	17,450	16,258
Cost of revenue	4,059	3,605	2,809
Sales and marketing	9,005	8,485	7,466
Loss from operations	6,489	5,360	5,983
Hosted Services - Business
Segment Reporting Information [Line Items]
Total revenue	197,474	178,686	183,551
Hosted Services - Business | Business | Operating Segments
Segment Reporting Information [Line Items]
Total revenue	197,474	178,686	183,551
Hosted Services - Consumer
Segment Reporting Information [Line Items]
Total revenue	19,553	17,450	16,258
Hosted Services - Consumer | Consumer | Operating Segments
Segment Reporting Information [Line Items]
Total revenue	19,553	17,450	16,258
Professional Services
Segment Reporting Information [Line Items]
Total revenue	32,811	22,740	22,970
Professional Services | Business | Operating Segments
Segment Reporting Information [Line Items]
Total revenue	$ 32,811	$ 22,740	$ 22,970

Segment Information - Long-Live

Segment Information - Long-Lived Assets By Geographic Region (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Segment Reporting Information [Line Items]
Total long-lived assets	$ 155,143	$ 127,487
United States
Segment Reporting Information [Line Items]
Total long-lived assets	122,019	93,845
Israel
Segment Reporting Information [Line Items]
Total long-lived assets	13,598	13,940
Australia
Segment Reporting Information [Line Items]
Total long-lived assets	8,970	9,496
Netherlands
Segment Reporting Information [Line Items]
Total long-lived assets	7,426	7,495
Other
Segment Reporting Information [Line Items]
Total long-lived assets	$ 3,130	$ 2,711

Property and Equipment - Balanc

Property and Equipment - Balances (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Property and Equipment, Net
Property and equipment gross	$ 112,533	$ 116,170
Less: accumulated depreciation	(68,798)	(81,465)
Total	43,735	34,705
Computer equipment and software
Property and Equipment, Net
Property and equipment gross	79,161	92,079
Furniture, equipment and building improvements
Property and Equipment, Net
Property and equipment gross	14,132	15,355
Internal-use software development costs
Property and Equipment, Net
Property and equipment gross	$ 19,240	$ 8,736

Property and Equipment - Narrat

Property and Equipment - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Property, Plant and Equipment [Abstract]
Internal-use software development costs not yet subject to amortization	$ 7,800
Depreciation expense	$ 14,188	$ 12,358	$ 12,011

Goodwill and Intangible Asset_2

Goodwill and Intangible Assets - Changes in Carrying Amount of Goodwill (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Goodwill [Roll Forward]
Beginning Balance	$ 80,531,000	$ 80,245,000
Acquisitions	14,606,000
Foreign exchange adjustments	(106,000)	286,000
Ending Balance	95,031,000	80,531,000	$ 80,245,000
Accumulated goodwill impairment charges	23,500,000
Impairment recognized	0	0	0
Business [Member]
Goodwill [Roll Forward]
Beginning Balance	72,507,000	72,221,000
Acquisitions	14,606,000
Foreign exchange adjustments	(106,000)	286,000
Ending Balance	87,007,000	72,507,000	72,221,000
Consumer
Goodwill [Roll Forward]
Beginning Balance	8,024,000	8,024,000
Acquisitions	0
Foreign exchange adjustments	0	0
Ending Balance	$ 8,024,000	$ 8,024,000	$ 8,024,000

Goodwill and Intangible Asset_3

Goodwill and Intangible Assets - Summary of Intangible Assets (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 52,724	$ 48,470
Accumulated Amortization	(38,892)	(36,104)
Net Carrying Amount	13,832	12,366
Technology
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	30,447	27,882
Accumulated Amortization	(23,615)	(22,197)
Net Carrying Amount	$ 6,832	$ 5,685
Weighted Average Amortization Period	5 years 3 months	5 years 3 months
Customer relationships
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 17,219	$ 15,978
Accumulated Amortization	(11,786)	(10,457)
Net Carrying Amount	$ 5,433	$ 5,521
Weighted Average Amortization Period	8 years 5 months	8 years
Trade names
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 1,286	$ 1,289
Accumulated Amortization	(1,286)	(1,283)
Net Carrying Amount	$ 0	$ 6
Weighted Average Amortization Period	2 years 1 month	2 years 1 month
Non-compete agreements
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 1,436	$ 1,439
Accumulated Amortization	(1,436)	(1,439)
Net Carrying Amount	$ 0	$ 0
Weighted Average Amortization Period	2 years 3 months	2 years 3 months
Patents
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 2,074	$ 1,620
Accumulated Amortization	(534)	(493)
Net Carrying Amount	$ 1,540	$ 1,127
Weighted Average Amortization Period	12 years 5 months	13 years 1 month
Other
Acquired Finite-Lived Intangible Assets [Line Items]
Gross Carrying Amount	$ 262	$ 262
Accumulated Amortization	(235)	(235)
Net Carrying Amount	$ 27	$ 27
Weighted Average Amortization Period	2 years 8 months	2 years 8 months

Goodwill and Intangible Asset_4

Goodwill and Intangible Assets - Summary of Amortization Expense (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Goodwill and Intangible Assets Disclosure [Abstract]
Amortization expense	$ 2,813	$ 4,682	$ 6,673
Estimated future amortization expense
2,019	2,901
2,020	2,708
2,021	2,498
2,022	2,143
2,023	902
Thereafter	2,680
Total	$ 13,832	$ 12,366

Accrued Liabilities and Other_3

Accrued Liabilities and Other Current Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Payables and Accruals [Abstract]
Payroll and other employee related costs	$ 19,014	$ 16,431
Professional services, consulting and other vendor fees	17,461	15,674
Unrecognized tax benefits	1,913	4,924
Sales commissions	6,239	5,259
Contingent earn-out (Note 8)	2,372	0
Restructuring Reserve	977	2,338	$ 2,551
Other	2,686	3,385
Total	$ 50,662	$ 48,011

Acquisitions - Narrative (Detai

Acquisitions - Narrative (Details) - USD ($) $ in Thousands	1 Months Ended			12 Months Ended
	Oct. 31, 2018	Sep. 30, 2018	Jan. 31, 2018	Dec. 31, 2018	Dec. 31, 2017
Business Acquisition [Line Items]
Goodwill acquired in acquisition				$ 14,606
Intangible assets acquired				$ 52,724	$ 48,470
AdvantageTec
Business Acquisition [Line Items]
Aggregate purchase price	$ 11,200
Cash payment in acquisition	6,000
Equity consideration in acquisition	4,300
Potential earn-out consideration payments based on achieving targets	900
Goodwill acquired in acquisition	9,100
Intangible assets acquired	2,200
Acquisition costs incurred	600
Deferred tax liability for intangible assets	500
Assets acquired liabilities assumed, net liability	$ (100)
Conversable
Business Acquisition [Line Items]
Aggregate purchase price		$ 5,700
Cash payment in acquisition		1,300
Equity consideration in acquisition		2,900
Potential earn-out consideration payments based on achieving targets		1,500
Goodwill acquired in acquisition		5,500
Intangible assets acquired		500
Assets acquired liabilities assumed, net liability		$ (300)
BotCentral
Business Acquisition [Line Items]
Equity consideration in acquisition			$ 1,000
Intangible assets acquired			1,200
Business acquisition transaction costs			$ 200

Fair Value Measurements - Narra

Fair Value Measurements - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Cash held as collateral	$ 0	$ 1,451
Additions to contingent earn-out	$ 2,400
Synchronite, LLC
Fair Value, Assets and Liabilities Measured on Recurring and Nonrecurring Basis [Line Items]
Payments on contingent earnout		$ 200

Fair Value Measurements - Asset

Fair Value Measurements - Assets and Liabilities Measured at Fair Value (Details) - Recurring - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Assets:
Total assets	$ 2,828	$ 2,871
Liabilities:
Total liabilities	2,372	2
Money market funds
Assets:
Money market funds	2,828	2,806
Contingent earn-out
Liabilities:
Contingent earn-out	2,372	0
Foreign currency derivative contracts
Assets:
Foreign currency derivative contracts	0	65
Liabilities:
Foreign currency derivative contracts	0	2
Level 1
Assets:
Total assets	2,828	2,806
Liabilities:
Total liabilities	0	0
Level 1 | Money market funds
Assets:
Money market funds	2,828	2,806
Level 1 | Contingent earn-out
Liabilities:
Contingent earn-out	0	0
Level 1 | Foreign currency derivative contracts
Assets:
Foreign currency derivative contracts	0	0
Liabilities:
Foreign currency derivative contracts	0	0
Level 2
Assets:
Total assets	0	65
Liabilities:
Total liabilities	0	2
Level 2 | Money market funds
Assets:
Money market funds	0	0
Level 2 | Contingent earn-out
Liabilities:
Contingent earn-out	0	0
Level 2 | Foreign currency derivative contracts
Assets:
Foreign currency derivative contracts	0	65
Liabilities:
Foreign currency derivative contracts	0	2
Level 3
Assets:
Total assets	0	0
Liabilities:
Total liabilities	2,372	0
Level 3 | Money market funds
Assets:
Money market funds	0	0
Level 3 | Contingent earn-out
Liabilities:
Contingent earn-out	2,372	0
Level 3 | Foreign currency derivative contracts
Assets:
Foreign currency derivative contracts	0	0
Liabilities:
Foreign currency derivative contracts	$ 0	$ 0

Fair Value Measurements - Level

Fair Value Measurements - Level 3 Liabilities (Details) - Contingent earn-out - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Balance, Beginning of year	$ 0	$ 210
Cash payment	0	(210)
Balance, End of year	2,372	0
Conversable
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Additions	1,496	0
AdvantageTec
Fair Value, Liabilities Measured on Recurring Basis, Unobservable Input Reconciliation, Calculation [Roll Forward]
Additions	$ 876	$ 0

Fair Value Measurements - Deriv

Fair Value Measurements - Derivative Financial Instruments (Details) - Foreign currency derivative contracts - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Derivative [Line Items]
Notional amount of foreign currency derivative contracts	$ 0	$ 2,866
Fair value of foreign currency derivatives contracts	0	63
Other (Expense) Income, net
Derivative [Line Items]
Gain (losses) on Derivative Instruments Recognized in Income Statement	(50)	236
Derivatives not designated as hedging instruments | Prepaid expenses and other current assets
Derivative Asset [Abstract]
Foreign currency derivative contracts	0	65
Derivatives not designated as hedging instruments | Accrued expenses and other liabilities
Derivative Liability [Abstract]
Foreign currency derivative contracts	$ 0	$ 2

Commitments and Contingencies -

Commitments and Contingencies - Narrative (Details) - USD ($)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Commitments and Contingencies Disclosure [Abstract]
Rental expense for operating leases	$ 10,900,000	$ 9,900,000	$ 10,000,000
Defined contribution plan employer matching contribution on first five percent of employee compensation	50.00%
Percentage of employees' eligible compensation for employer matching contribution	5.00%
Defined contribution plan employer contribution limit	$ 6,000
Defined contribution plan employer contribution vesting period	5 years
Defined benefit plan employer contribution	$ 1,600,000	$ 1,400,000	$ 1,300,000
LOC for Office Space
Other Contingencies [Line Items]
Letters of credit outstanding	1,800,000
LOC for Security Deposit
Other Contingencies [Line Items]
Letters of credit outstanding	$ 100,000

Commitments and Contingencies_2

Commitments and Contingencies - Future Minimum Lease Payments Under Non-Cancelable Operating Leases (Details) $ in Thousands	Dec. 31, 2018USD ($)
Future Minimum Lease Payments
2,019	$ 8,488
2,020	6,139
2,021	5,477
2,022	2,649
2,023	883
Thereafter	61
Total minimum lease payments	$ 23,697

Stockholders' Equity - Narrativ

Stockholders' Equity - Narrative (Details) - USD ($) $ / shares in Units, $ in Millions	Jun. 02, 2017	Jun. 07, 2012	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2009	Dec. 31, 2000	Mar. 31, 2018	Jun. 30, 2010	Dec. 31, 1998
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Common stock, shares authorized (in shares)			100,000,000	100,000,000
Common stock, shares issued (in shares)			63,676,229	59,663,969
Common stock, shares outstanding (in shares)			63,676,229	59,663,969
Common stock, par value (in dollars per share)			$ 0.001	$ 0.001
Preferred stock, shares authorized (in shares)			5,000,000	5,000,000,000
Preferred stock, shares issued (in shares)			0	0
Preferred stock, shares outstanding (in shares)			0	0
Preferred stock, par value (in dollars per share)			$ 0.001	$ 0.001
Weighted average fair value of stock options granted (in dollars per share)			$ 6.60	$ 4.25	$ 3.10
Dividend yield			0.00%	0.00%	0.00%
Expected life (in years)			5 years	5 years	5 years
Volatility determination period (in years)			5 years
Fair value of stock options exercised			$ 16.1	$ 3.7
2010 Employee Stock Purchase Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares of common stock authorized and reserved for issuance (in shares)									1,000,000
Amended and Restated 2010 Employee Stock Purchase Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares of common stock authorized and reserved for issuance (in shares)	2,000,000
Increase in number of shares of common stock available for issuance (in shares)	1,000,000
Common shares reserved for future issuance (in shares)			877,822
2018 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares of common stock authorized and reserved for issuance (in shares)			2,000,000					1,500,000
Increase in number of shares of common stock available for issuance (in shares)			500,000
Common shares reserved for future issuance (in shares)			100,000
Incentive Stock Option
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Unrecognized compensation cost			$ 14.4
Weighted average recognition period of unrecognized compensation cost			2 years 8 months 12 days
Incentive Stock Option | 1998 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares of common stock authorized and reserved for issuance (in shares)										5,850,000
Incentive Stock Option | 2000 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares of common stock authorized and reserved for issuance (in shares)							10,000,000
Increase in number of shares of common stock available for issuance (in shares)							4,150,000
Incentive Stock Option | 2009 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Increase in number of shares of common stock available for issuance (in shares)						6,000,000
Incentive Stock Option | Amended 2009 Plan
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Shares of common stock authorized and reserved for issuance (in shares)	23,817,744
Increase in number of shares of common stock available for issuance (in shares)	4,000,000	4,250,000
Shares of common stock available for issuance (in shares)			2,700,000
Stock option term			10 years
Restricted Stock Units (RSUs)
Share-based Compensation Arrangement by Share-based Payment Award [Line Items]
Vesting period (in years)			4 years
Unrecognized compensation cost			$ 37.9
Weighted average recognition period of unrecognized compensation cost			2 years 9 months 12 days

Stockholders' Equity - Weighted

Stockholders' Equity - Weighted Average Assumptions of Fair Value Options Using Black-Scholes Option-Pricing Model (Details)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Equity [Abstract]
Dividend yield	0.00%	0.00%	0.00%
Risk-free interest rate, minimum	2.50%	1.70%	1.00%
Risk-free interest rate, maximum	3.10%	2.10%	1.80%
Expected life (in years)	5 years	5 years	5 years
Historical volatility, minimum	43.50%	46.60%	46.80%
Historical volatility, maximum	48.40%	48.10%	48.20%

Stockholders' Equity - Summary

Stockholders' Equity - Summary of Stock Option Activity and Weighted Average Exercise Prices (Details) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Options
Options outstanding, beginning balance (in shares)	7,959	7,769	9,144
Granted (in shares)	2,033	2,042	635
Exercised (in shares)	(3,120)	(854)	(325)
Cancelled or expired (in shares)	(606)	(998)	(1,685)
Options outstanding, ending balance (in shares)	6,266	7,959	7,769
Options vested and expected to vest	5,550	7,163	7,348
Options exercisable	3,278	5,163	5,580
Weighted Average Exercise Price
Options outstanding, beginning balance (in dollars per share)	$ 10.71	$ 10.88	$ 11.05
Granted (in dollars per share)	15	9.87	7.32
Exercised (in dollars per share)	10.70	8.80	5.66
Cancelled (in dollars per share)	10.03	11.98	11.49
Options outstanding, ending balance (in dollars per share)	12.13	10.71	10.88
Options vested and expected to vest (in dollars per share)	11.89	10.75	11
Options exercisable (in dollars per share)	$ 11.12	$ 11.17	$ 11.31
Weighted Average Remaining Contractual Term (in years)
Options outstanding	6 years 6 months 18 days	5 years 10 months 6 days	6 years 18 days
Options vested and expected to vest	6 years 3 months 11 days	5 years 5 months 27 days	5 years 10 months 24 days
Options exercisable	4 years 7 months 21 days	4 years 6 months	5 years 3 months 7 days
Aggregate Intrinsic Value
Options outstanding	$ 43,348	$ 14,881	$ 2,641
Options vested and expected to vest	39,521	13,197	2,529
Options exercisable	$ 25,367	$ 8,648	$ 2,347

Stockholders' Equity - Summar_2

Stockholders' Equity - Summary of Outstanding and Vested Options (Details) shares in Thousands	12 Months Ended
	Dec. 31, 2018$ / sharesshares
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Options Outstanding, Number of Shares Outstanding | shares	6,266
Options Outstanding, Weighted-Average Remaining Contractual Life (Years)	6 years 6 months 18 days
Options Outstanding, Weighted-Average Exercise Price (in dollars per share)	$ 12.13
Options Exercisable, Number of Shares | shares	3,278
Options Exercisable, Weighted-Average Exercise Price (in dollars per share)	$ 11.12
$1.79 - $7.60
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price range, minimum (in dollars per share)	1.79000
Exercise price range, maximum (in dollars per share)	$ 7.60000
Options Outstanding, Number of Shares Outstanding | shares	1,081
Options Outstanding, Weighted-Average Remaining Contractual Life (Years)	6 years 4 months 13 days
Options Outstanding, Weighted-Average Exercise Price (in dollars per share)	$ 7.03
Options Exercisable, Number of Shares | shares	570
Options Exercisable, Weighted-Average Exercise Price (in dollars per share)	$ 6.70
$7.95 - $9.55
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price range, minimum (in dollars per share)	7.95000
Exercise price range, maximum (in dollars per share)	$ 9.55000
Options Outstanding, Number of Shares Outstanding | shares	635
Options Outstanding, Weighted-Average Remaining Contractual Life (Years)	5 years 10 months 24 days
Options Outstanding, Weighted-Average Exercise Price (in dollars per share)	$ 9.20
Options Exercisable, Number of Shares | shares	488
Options Exercisable, Weighted-Average Exercise Price (in dollars per share)	$ 9.18
$9.90 - $10.13
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price range, minimum (in dollars per share)	9.90000
Exercise price range, maximum (in dollars per share)	$ 10.13000
Options Outstanding, Number of Shares Outstanding | shares	640
Options Outstanding, Weighted-Average Remaining Contractual Life (Years)	5 years 4 months
Options Outstanding, Weighted-Average Exercise Price (in dollars per share)	$ 10.09
Options Exercisable, Number of Shares | shares	636
Options Exercisable, Weighted-Average Exercise Price (in dollars per share)	$ 10.09
$10.31 - $11.96
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price range, minimum (in dollars per share)	10.31000
Exercise price range, maximum (in dollars per share)	$ 11.96000
Options Outstanding, Number of Shares Outstanding | shares	660
Options Outstanding, Weighted-Average Remaining Contractual Life (Years)	6 years 9 months 8 days
Options Outstanding, Weighted-Average Exercise Price (in dollars per share)	$ 11.26
Options Exercisable, Number of Shares | shares	388
Options Exercisable, Weighted-Average Exercise Price (in dollars per share)	$ 11
$12.09 - $12.32
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price range, minimum (in dollars per share)	12.09000
Exercise price range, maximum (in dollars per share)	$ 12.32000
Options Outstanding, Number of Shares Outstanding | shares	39
Options Outstanding, Weighted-Average Remaining Contractual Life (Years)	2 years 3 months 22 days
Options Outstanding, Weighted-Average Exercise Price (in dollars per share)	$ 12.29
Options Exercisable, Number of Shares | shares	39
Options Exercisable, Weighted-Average Exercise Price (in dollars per share)	$ 12.29
$12.45 - $12.45
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price range, minimum (in dollars per share)	12.45000
Exercise price range, maximum (in dollars per share)	$ 12.45000
Options Outstanding, Number of Shares Outstanding | shares	930
Options Outstanding, Weighted-Average Remaining Contractual Life (Years)	9 years 1 month 18 days
Options Outstanding, Weighted-Average Exercise Price (in dollars per share)	$ 12.45
Options Exercisable, Number of Shares | shares	0
Options Exercisable, Weighted-Average Exercise Price (in dollars per share)	$ 0
$12.46 - $13.59
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price range, minimum (in dollars per share)	12.46000
Exercise price range, maximum (in dollars per share)	$ 13.59000
Options Outstanding, Number of Shares Outstanding | shares	684
Options Outstanding, Weighted-Average Remaining Contractual Life (Years)	3 years 5 months
Options Outstanding, Weighted-Average Exercise Price (in dollars per share)	$ 13.31
Options Exercisable, Number of Shares | shares	684
Options Exercisable, Weighted-Average Exercise Price (in dollars per share)	$ 13.31
$14.30 - $15.96
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price range, minimum (in dollars per share)	14.30000
Exercise price range, maximum (in dollars per share)	$ 15.96000
Options Outstanding, Number of Shares Outstanding | shares	678
Options Outstanding, Weighted-Average Remaining Contractual Life (Years)	7 years 2 months 18 days
Options Outstanding, Weighted-Average Exercise Price (in dollars per share)	$ 14.73
Options Exercisable, Number of Shares | shares	146
Options Exercisable, Weighted-Average Exercise Price (in dollars per share)	$ 14.97
$16.05 - $21.75
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price range, minimum (in dollars per share)	16.05000
Exercise price range, maximum (in dollars per share)	$ 21.75000
Options Outstanding, Number of Shares Outstanding | shares	770
Options Outstanding, Weighted-Average Remaining Contractual Life (Years)	6 years 10 months 5 days
Options Outstanding, Weighted-Average Exercise Price (in dollars per share)	$ 18.30
Options Exercisable, Number of Shares | shares	327
Options Exercisable, Weighted-Average Exercise Price (in dollars per share)	$ 17.45
$22.04 - $23.50
Share-based Compensation, Shares Authorized under Stock Option Plans, Exercise Price Range [Line Items]
Exercise price range, minimum (in dollars per share)	22.04000
Exercise price range, maximum (in dollars per share)	$ 23.50000
Options Outstanding, Number of Shares Outstanding | shares	149
Options Outstanding, Weighted-Average Remaining Contractual Life (Years)	9 years 6 months 22 days
Options Outstanding, Weighted-Average Exercise Price (in dollars per share)	$ 22.91
Options Exercisable, Number of Shares | shares	0
Options Exercisable, Weighted-Average Exercise Price (in dollars per share)	$ 0

Stockholders' Equity - Summar_3

Stockholders' Equity - Summary of Restricted Stock Unit Activity (Details) - Restricted Stock Units (RSUs) - USD ($) $ / shares in Units, shares in Thousands, $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016	Dec. 31, 2015
Share-based Compensation Arrangement by Share-based Payment Award, Equity Instruments Other than Options, Nonvested, Number of Shares [Roll Forward]
Balance outstanding, beginning (shares)	873	1,188	1,202
Awarded (shares)	2,568	332	571
Released (shares)	(361)	(363)	(394)
Forfeited (shares)	(390)	(284)	(191)
Non-vested and outstanding, ending (shares)	2,690	873	1,188
Expected to vest (shares)	1,875
Weighted Average Grant Date Fair Value (Per Share)
Balance outstanding, beginning (in dollars per share)	$ 8.29	$ 8.44	$ 10.31
Awarded (in dollars per share)	17.02	8.16	6.32
Released (in dollars per share)	9.49	8.48	10.31
Forfeited (in dollars per share)	9.49	8.46	10.01
Non-vested and outstanding, ending (in dollars per share)	15.81	$ 8.29	$ 8.44
Expected to vest (in dollars per share)	$ 14.83
Aggregate Fair Value
Non-vested and outstanding	$ 50,756	$ 10,053	$ 8,968	$ 6,220
Expected to vest	$ 35,357
Vesting period (in years)	4 years

Income Taxes - Narrative (Detai

Income Taxes - Narrative (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Operating Loss Carryforwards [Line Items]
Valuation recorded		$ 6,900
Net operating loss carryforwards	$ 8,093	18,083	$ 8,093
Unrecognized tax benefits	4,924	1,921	4,924	$ 4,240
Decrease in unrecognized tax benefits that is reasonably possible		1,000
Settlements of audit		2,963	0
Decrease in federal deferred tax provision upon remeasurement of net deferred taxes at newly enacted rate, provisional estimate	10,100
Federal deferred tax benefit upon remeasurement of valuation allowance at newly enacted rate, provisional estimate	12,600
Federal deferred tax benefit for indefinite lived deferred tax liabilities, provisional estimate	$ 2,000
Percentage of indefinite-lived deferred tax liabilities (percent)	80.00%
State deferred tax provision	$ 1,200	(28)	(1,144)	$ 99
Federal
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards		73,000
Operating loss carryforwards generated in taxable years ending on or before December 31 2017	$ 32,800	32,800	$ 32,800
Net operating loss carryforwards		74,200
Net operating loss carryforwards, not subject to expiration		$ 39,200
Operating loss carryforwards, period of carryforward (in years)		20 years
Federal | Expiration between 2023 and 2026
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards, subject to expiration		$ 6,000
Federal | Expiration between 2036 and 2037
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards, subject to expiration		28,900
Federal | Proficient [Member]
Operating Loss Carryforwards [Line Items]
Operating loss carryforwards		5,100
Foreign | Australian Taxation Office
Operating Loss Carryforwards [Line Items]
Net operating loss carryforwards		5,300
Foreign | Israel Tax Authority
Operating Loss Carryforwards [Line Items]
Settlements of audit		$ 3,000

Income Taxes - Domestic and For

Income Taxes - Domestic and Foreign Components of Income Before Provision for Income Taxes (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Tax Contingency [Line Items]
United States	$ (38,078)	$ (25,585)	$ (40,774)
(Loss) income before provision for (benefit from) income taxes	(24,174)	(17,690)	(19,939)
Israel
Income Tax Contingency [Line Items]
Foreign	3,163	3,458	15,622
United Kingdom
Income Tax Contingency [Line Items]
Foreign	3,690	2,087	2,345
Netherlands
Income Tax Contingency [Line Items]
Foreign	3,235	1,568	3,104
Australia
Income Tax Contingency [Line Items]
Foreign	686	(1,979)	(2,774)
Germany [Member]
Income Tax Contingency [Line Items]
Foreign	2,900	2,424	2,085
Japan [Member]
Income Tax Contingency [Line Items]
Foreign	$ 230	$ 337	$ 453

Income Taxes - Schedule of Prov

Income Taxes - Schedule of Provision for Income Taxes (Details) - USD ($) $ in Thousands	3 Months Ended	12 Months Ended
	Dec. 31, 2017	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Current income taxes:
Current income taxes, U.S. Federal		$ (1,932)	$ 0	$ 1,829
Current income taxes, State and local		67	47	27
Current income taxes, Foreign		3,032	2,852	2,226
Total current income taxes		1,167	2,899	4,082
Deferred income taxes:
Deferred income taxes, U.S. Federal		(295)	(1,289)	841
Deferred income taxes, State and local	$ 1,200	(28)	(1,144)	99
Deferred income taxes, Foreign		14	35	912
Total deferred income taxes		(309)	(2,398)	1,852
Total income taxes		$ 858	$ 501	$ 5,934

Income Taxes - Schedule of Reco

Income Taxes - Schedule of Reconciliations of Federal Statutory Tax Rate to Effective Income Tax Rate (Details)	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Income Tax Disclosure [Abstract]
Federal statutory rate	21.00%	34.00%	34.00%
State taxes, net of federal benefit	3.30%	4.09%	3.24%
Non-deductible expenses – ISO	4.73%	(0.78%)	(1.85%)
Global intangible low tax income inclusion	(7.99%)	0.00%	0.00%
Non-deductible expenses – Other	(2.58%)	(1.19%)	(0.88%)
Foreign tax rate differential	(1.34%)	(1.97%)	0.89%
Change in valuation allowance	(28.91%)	26.12%	(53.55%)
Stock based compensation	6.10%	0.00%	0.00%
Return to provision true-up adjustment	0.00%	0.00%	(9.22%)
Effect of new tax legislation	0.00%	(56.84%)
Other	2.09%	(6.26%)	(2.42%)
Total provision for income taxes	(3.60%)	(2.83%)	(29.79%)

Income Taxes - Schedule of Fede

Income Taxes - Schedule of Federal Deferred Tax Assets and Deferred Tax Liabilities (Details) - USD ($) $ in Thousands	Dec. 31, 2018	Dec. 31, 2017
Deferred tax assets:
Net operating loss carryforwards	$ 18,083	$ 8,093
Accounts payable and accrued expenses	4,024	4,429
Non-cash compensation	9,597	9,510
Intangibles amortization	5,691	5,513
Allowance for doubtful accounts	315	232
Total deferred tax assets	37,710	27,777
Less valuation allowance	(30,185)	(23,260)
Deferred tax assets, net of valuation allowance	7,525	4,517
Deferred tax liabilities:
Property and equipment	(3,736)	(2,010)
Goodwill amortization and contingent earn-out adjustments	(4,172)	(2,669)
Total deferred tax liabilities	(7,908)	(4,679)
Net deferred (liabilities)	$ (383)	$ (162)

Income Taxes - Schedule of Unre

Income Taxes - Schedule of Unrecognized Tax Benefits (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Reconciliation of Unrecognized Tax Benefits, Excluding Amounts Pertaining to Examined Tax Returns [Roll Forward]
Unrecognized tax benefits balance at January 1	$ 4,924	$ 4,240
Gross increase for tax positions of prior years	0	0
Gross increase for tax positions of current years	405	684
Decrease due to expiration of statue	(445)	0
Decrease due to settlement	(2,963)	0
Gross unrecognized tax benefits at December 31	$ 1,921	$ 4,924

Restructuring Costs - Narrative

Restructuring Costs - Narrative (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Restructuring Cost and Reserve [Line Items]
Restructuring charges		$ 4,468	$ 2,594	$ 2,369
Restructuring liability		$ 977	$ 2,338	$ 2,551
Forecast
Restructuring Cost and Reserve [Line Items]
Restructuring charges	$ 300

Restructuring Costs - Component

Restructuring Costs - Components of Restructuring Charges (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017
Restructuring Reserve [Roll Forward]
Balance, Beginning of the year	$ 2,338	$ 2,551
Severance and other associated costs	4,468	648
Cash payments	(5,829)	(2,807)
Wind down costs of legacy platform	0	1,946
Balance, End of year	$ 977	$ 2,338

Restructuring Costs - Expenses

Restructuring Costs - Expenses Related to Restructuring Charges (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2018	Dec. 31, 2017	Dec. 31, 2016
Restructuring Cost and Reserve [Line Items]
Restructuring charges	$ 4,468	$ 2,594	$ 2,369
Contract termination costs
Restructuring Cost and Reserve [Line Items]
Restructuring charges	0	0	(384)
Severance and other associated costs
Restructuring Cost and Reserve [Line Items]
Restructuring charges	4,468	648	1,585
Wind down costs of legacy platform
Restructuring Cost and Reserve [Line Items]
Restructuring charges	$ 0	$ 1,946	$ 1,168